Devart Forums

Posted: **Thu 02 Feb 2012 14:07**

Hi,
I've just experienced the same problem posted on http://www.devart.com/forums/viewtopic.php?p=78102. IDE or not, I still get a "Lost connection to MySQL server during query". Full Exception stack is below.

My setup was as follows:
I had a connection open, and I was iterating over ~6000 records (as an IQueryable), taking data from each record and constructing a new OR object (the new OR objects are detached from the context). Each new OR object went into an IList which later would be BulkLoaded, but I never get that far. About 70-80 records into my foreach loop, I encounter the problem below.

My timeout parameters at the server are long. Nothing is shorter than 5 minutes; this occurs a few seconds into my process.

I see that dotConnect for MySql 6.70 is out, but I don't want to upgrade (yet - I am running 6.50.250) unless there is some known issue in there that would address this.

Any help would greatly be appreciated.
Thanks!

Error on reading data from IDataReader.
at Devart.Data.Linq.LinqCommandExecutionException.CanThrowLinqCommandExecutionException(String message, Exception e)
at Devart.Data.Linq.Provider.ObjectReader`1.MoveNext()
at System.Linq.Seq.d__20`1.MoveNext() in C:\dev\wrkspc.......:line 486
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
at Extract.KPIs() in C:\dev\wrkspc.................:line 162
Lost connection to MySQL server during query
at Devart.Common.aj.a(Exception A_0)
at Devart.Data.MySql.bh.a(Exception A_0)
at Devart.Common.s.e(Byte[] A_0, Int32 A_1, Int32 A_2)
at Devart.Data.MySql.bk.a(Byte[] A_0, Int32 A_1, Int32 A_2)
at Devart.Data.MySql.bk.a()
at Devart.Data.MySql.bk.b(Byte[] A_0)
at Devart.Data.MySql.u.a(Byte[] A_0)
at Devart.Data.MySql.u.a(Byte[] A_0, Boolean A_1)
at Devart.Data.MySql.an.f()
at Devart.Data.MySql.a2.b(Boolean A_0)
at Devart.Data.MySql.MySqlDataReader.a(Boolean A_0)
at Devart.Data.MySql.MySqlDataReader.System.IDisposable.Dispose()
at Devart.Common.l.a(Int32 A_0, Object A_1, Int32 A_2, Object A_3)
at Devart.Common.l.a.a(Int32 A_0, Int32 A_1, Object A_2, l A_3)
at Devart.Common.l.a(Int32 A_0, Int32 A_1, Object A_2)
at Devart.Common.DbConnectionInternal.a(Int32 A_0, Int32 A_1)
at Devart.Common.DbConnectionBase.Close()
at Devart.Data.MySql.MySqlConnection.Close()

Posted: **Fri 03 Feb 2012 06:30**

I just confirmed that my entire workflow works just fine, so long as the initial data set I am looping through does not exceed 80 records. Is there a paging limit I need to set somewhere??

Thanks!

Posted: **Fri 03 Feb 2012 16:54**

Could you please specify the following:
- the data types available in the table you are querying (if possible, please specify the script needed to create this table);
- an approximate size of a row in this table;
- the version of the MySQL server you are working with;
- the list of server variables.

For example, this issue may occur if the table contains large BLOB or text data, and the max_allowed_packet server variable is small.

Posted: **Fri 03 Feb 2012 18:35**

Data Types in table are: INT(11), DateTime, VarChar, and Text. The specific result set I am trying to iterate over actually returns ~4k rows, each containing a TEXT object that is ~4k ~4.5k characters in length.

I am running MySQL 5.0.51a-3ubuntu5.8.

Variables is use are below, and the max_allowed_packet size is 16776192. That's about 15MB. Is that limit per row, or per set? My result set is 4300 rows, ~275MB. Currently, I do the following:

IQueryable match = _context.Metrics.Where(c => (c.Name.Equals(kpi.MetricName)));

And I loop over the IQueryable result set in a foreach loop.

That IQueryable result set is the large problematic one. Is there a recommended way to page/loop through a set like that?

Thanks!

Code: Select all

=======================================================================================================
|                  Variable_name                   |                      Value                       |
=======================================================================================================
|             auto_increment_increment             |                        1                         |
-------------------------------------------------------------------------------------------------------
|              auto_increment_offset               |                        1                         |
-------------------------------------------------------------------------------------------------------
|             automatic_sp_privileges              |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                     back_log                     |                        50                        |
-------------------------------------------------------------------------------------------------------
|                     basedir                      |                      /usr/                       |
-------------------------------------------------------------------------------------------------------
|                binlog_cache_size                 |                      32768                       |
-------------------------------------------------------------------------------------------------------
|             bulk_insert_buffer_size              |                     8388608                      |
-------------------------------------------------------------------------------------------------------
|               character_set_client               |                       utf8                       |
-------------------------------------------------------------------------------------------------------
|             character_set_connection             |                       utf8                       |
-------------------------------------------------------------------------------------------------------
|              character_set_database              |                       utf8                       |
-------------------------------------------------------------------------------------------------------
|             character_set_filesystem             |                      binary                      |
-------------------------------------------------------------------------------------------------------
|              character_set_results               |                       utf8                       |
-------------------------------------------------------------------------------------------------------
|               character_set_server               |                      latin1                      |
-------------------------------------------------------------------------------------------------------
|               character_set_system               |                       utf8                       |
-------------------------------------------------------------------------------------------------------
|                character_sets_dir                |            /usr/share/mysql/charsets/            |
-------------------------------------------------------------------------------------------------------
|               collation_connection               |                 utf8_general_ci                  |
-------------------------------------------------------------------------------------------------------
|                collation_database                |                 utf8_general_ci                  |
-------------------------------------------------------------------------------------------------------
|                 collation_server                 |                latin1_swedish_ci                 |
-------------------------------------------------------------------------------------------------------
|                 completion_type                  |                        0                         |
-------------------------------------------------------------------------------------------------------
|                concurrent_insert                 |                        1                         |
-------------------------------------------------------------------------------------------------------
|                 connect_timeout                  |                       300                        |
-------------------------------------------------------------------------------------------------------
|                     datadir                      |                 /var/lib/mysql/                  |
-------------------------------------------------------------------------------------------------------
|                   date_format                    |                     %Y-%m-%d                     |
-------------------------------------------------------------------------------------------------------
|                 datetime_format                  |                %Y-%m-%d %H:%i:%s                 |
-------------------------------------------------------------------------------------------------------
|               default_week_format                |                        0                         |
-------------------------------------------------------------------------------------------------------
|                 delay_key_write                  |                        ON                        |
-------------------------------------------------------------------------------------------------------
|               delayed_insert_limit               |                       100                        |
-------------------------------------------------------------------------------------------------------
|              delayed_insert_timeout              |                       300                        |
-------------------------------------------------------------------------------------------------------
|                delayed_queue_size                |                       1000                       |
-------------------------------------------------------------------------------------------------------
|             div_precision_increment              |                        4                         |
-------------------------------------------------------------------------------------------------------
|               keep_files_on_create               |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|            engine_condition_pushdown             |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                 expire_logs_days                 |                        10                        |
-------------------------------------------------------------------------------------------------------
|                      flush                       |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                    flush_time                    |                        0                         |
-------------------------------------------------------------------------------------------------------
|                ft_boolean_syntax                 |                  + -><()~*:""&|                  |
-------------------------------------------------------------------------------------------------------
|                 ft_max_word_len                  |                        84                        |
-------------------------------------------------------------------------------------------------------
|                 ft_min_word_len                  |                        4                         |
-------------------------------------------------------------------------------------------------------
|             ft_query_expansion_limit             |                        20                        |
-------------------------------------------------------------------------------------------------------
|                 ft_stopword_file                 |                    (built-in)                    |
-------------------------------------------------------------------------------------------------------
|               group_concat_max_len               |                       1024                       |
-------------------------------------------------------------------------------------------------------
|                   have_archive                   |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                     have_bdb                     |                        NO                        |
-------------------------------------------------------------------------------------------------------
|              have_blackhole_engine               |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                  have_compress                   |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                    have_crypt                    |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                     have_csv                     |                       YES                        |
-------------------------------------------------------------------------------------------------------
|               have_dynamic_loading               |                       YES                        |
-------------------------------------------------------------------------------------------------------
|               have_example_engine                |                        NO                        |
-------------------------------------------------------------------------------------------------------
|              have_federated_engine               |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                  have_geometry                   |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                   have_innodb                    |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                    have_isam                     |                        NO                        |
-------------------------------------------------------------------------------------------------------
|                have_merge_engine                 |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                 have_ndbcluster                  |                     DISABLED                     |
-------------------------------------------------------------------------------------------------------
|                   have_openssl                   |                     DISABLED                     |
-------------------------------------------------------------------------------------------------------
|                     have_ssl                     |                     DISABLED                     |
-------------------------------------------------------------------------------------------------------
|                 have_query_cache                 |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                    have_raid                     |                        NO                        |
-------------------------------------------------------------------------------------------------------
|                 have_rtree_keys                  |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                   have_symlink                   |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                     hostname                     |                  coverity-lnx01                  |
-------------------------------------------------------------------------------------------------------
|                   init_connect                   |                                                  |
-------------------------------------------------------------------------------------------------------
|                    init_file                     |                                                  |
-------------------------------------------------------------------------------------------------------
|                    init_slave                    |                                                  |
-------------------------------------------------------------------------------------------------------
|         innodb_additional_mem_pool_size          |                     1048576                      |
-------------------------------------------------------------------------------------------------------
|           innodb_autoextend_increment            |                        8                         |
-------------------------------------------------------------------------------------------------------
|          innodb_buffer_pool_awe_mem_mb           |                        0                         |
-------------------------------------------------------------------------------------------------------
|             innodb_buffer_pool_size              |                     8388608                      |
-------------------------------------------------------------------------------------------------------
|                 innodb_checksums                 |                        ON                        |
-------------------------------------------------------------------------------------------------------
|            innodb_commit_concurrency             |                        0                         |
-------------------------------------------------------------------------------------------------------
|            innodb_concurrency_tickets            |                       500                        |
-------------------------------------------------------------------------------------------------------
|              innodb_data_file_path               |              ibdata1:10M:autoextend              |
-------------------------------------------------------------------------------------------------------
|               innodb_data_home_dir               |                                                  |
-------------------------------------------------------------------------------------------------------
|                innodb_doublewrite                |                        ON                        |
-------------------------------------------------------------------------------------------------------
|               innodb_fast_shutdown               |                        1                         |
-------------------------------------------------------------------------------------------------------
|              innodb_file_io_threads              |                        4                         |
-------------------------------------------------------------------------------------------------------
|              innodb_file_per_table               |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|          innodb_flush_log_at_trx_commit          |                        1                         |
-------------------------------------------------------------------------------------------------------
|               innodb_flush_method                |                                                  |
-------------------------------------------------------------------------------------------------------
|              innodb_force_recovery               |                        0                         |
-------------------------------------------------------------------------------------------------------
|             innodb_lock_wait_timeout             |                        50                        |
-------------------------------------------------------------------------------------------------------
|          innodb_locks_unsafe_for_binlog          |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|               innodb_log_arch_dir                |                                                  |
-------------------------------------------------------------------------------------------------------
|                innodb_log_archive                |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|              innodb_log_buffer_size              |                     1048576                      |
-------------------------------------------------------------------------------------------------------
|               innodb_log_file_size               |                     5242880                      |
-------------------------------------------------------------------------------------------------------
|            innodb_log_files_in_group             |                        2                         |
-------------------------------------------------------------------------------------------------------
|            innodb_log_group_home_dir             |                        ./                        |
-------------------------------------------------------------------------------------------------------
|            innodb_max_dirty_pages_pct            |                        90                        |
-------------------------------------------------------------------------------------------------------
|               innodb_max_purge_lag               |                        0                         |
-------------------------------------------------------------------------------------------------------
|            innodb_mirrored_log_groups            |                        1                         |
-------------------------------------------------------------------------------------------------------
|                innodb_open_files                 |                       300                        |
-------------------------------------------------------------------------------------------------------
|            innodb_rollback_on_timeout            |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                innodb_support_xa                 |                        ON                        |
-------------------------------------------------------------------------------------------------------
|              innodb_sync_spin_loops              |                        20                        |
-------------------------------------------------------------------------------------------------------
|                innodb_table_locks                |                        ON                        |
-------------------------------------------------------------------------------------------------------
|            innodb_thread_concurrency             |                        8                         |
-------------------------------------------------------------------------------------------------------
|            innodb_thread_sleep_delay             |                      10000                       |
-------------------------------------------------------------------------------------------------------
|               interactive_timeout                |                      28800                       |
-------------------------------------------------------------------------------------------------------
|                 join_buffer_size                 |                      131072                      |
-------------------------------------------------------------------------------------------------------
|                 key_buffer_size                  |                     16777216                     |
-------------------------------------------------------------------------------------------------------
|             key_cache_age_threshold              |                       300                        |
-------------------------------------------------------------------------------------------------------
|               key_cache_block_size               |                       1024                       |
-------------------------------------------------------------------------------------------------------
|             key_cache_division_limit             |                       100                        |
-------------------------------------------------------------------------------------------------------
|                     language                     |            /usr/share/mysql/english/             |
-------------------------------------------------------------------------------------------------------
|               large_files_support                |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                 large_page_size                  |                        0                         |
-------------------------------------------------------------------------------------------------------
|                   large_pages                    |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                  lc_time_names                   |                      en_US                       |
-------------------------------------------------------------------------------------------------------
|                     license                      |                       GPL                        |
-------------------------------------------------------------------------------------------------------
|                   local_infile                   |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                 locked_in_memory                 |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                       log                        |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                     log_bin                      |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|         log_bin_trust_function_creators          |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                    log_error                     |                                                  |
-------------------------------------------------------------------------------------------------------
|          log_queries_not_using_indexes           |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                log_slave_updates                 |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                 log_slow_queries                 |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                   log_warnings                   |                        1                         |
-------------------------------------------------------------------------------------------------------
|                 long_query_time                  |                        10                        |
-------------------------------------------------------------------------------------------------------
|               low_priority_updates               |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|              lower_case_file_system              |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|              lower_case_table_names              |                        0                         |
-------------------------------------------------------------------------------------------------------
|                max_allowed_packet                |                     16776192                     |
-------------------------------------------------------------------------------------------------------
|              max_binlog_cache_size               |               18446744073709551615               |
-------------------------------------------------------------------------------------------------------
|                 max_binlog_size                  |                    104857600                     |
-------------------------------------------------------------------------------------------------------
|                max_connect_errors                |                        10                        |
-------------------------------------------------------------------------------------------------------
|                 max_connections                  |                       100                        |
-------------------------------------------------------------------------------------------------------
|               max_delayed_threads                |                        20                        |
-------------------------------------------------------------------------------------------------------
|                 max_error_count                  |                        64                        |
-------------------------------------------------------------------------------------------------------
|               max_heap_table_size                |                     16777216                     |
-------------------------------------------------------------------------------------------------------
|            max_insert_delayed_threads            |                        20                        |
-------------------------------------------------------------------------------------------------------
|                  max_join_size                   |               18446744073709551615               |
-------------------------------------------------------------------------------------------------------
|             max_length_for_sort_data             |                       1024                       |
-------------------------------------------------------------------------------------------------------
|             max_prepared_stmt_count              |                      16382                       |
-------------------------------------------------------------------------------------------------------
|                max_relay_log_size                |                        0                         |
-------------------------------------------------------------------------------------------------------
|                max_seeks_for_key                 |               18446744073709551615               |
-------------------------------------------------------------------------------------------------------
|                 max_sort_length                  |                       1024                       |
-------------------------------------------------------------------------------------------------------
|              max_sp_recursion_depth              |                        0                         |
-------------------------------------------------------------------------------------------------------
|                  max_tmp_tables                  |                        32                        |
-------------------------------------------------------------------------------------------------------
|               max_user_connections               |                        0                         |
-------------------------------------------------------------------------------------------------------
|               max_write_lock_count               |               18446744073709551615               |
-------------------------------------------------------------------------------------------------------
|                multi_range_count                 |                       256                        |
-------------------------------------------------------------------------------------------------------
|             myisam_data_pointer_size             |                        6                         |
-------------------------------------------------------------------------------------------------------
|            myisam_max_sort_file_size             |               9223372036854775807                |
-------------------------------------------------------------------------------------------------------
|              myisam_recover_options              |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|              myisam_repair_threads               |                        1                         |
-------------------------------------------------------------------------------------------------------
|             myisam_sort_buffer_size              |                     8388608                      |
-------------------------------------------------------------------------------------------------------
|               myisam_stats_method                |                  nulls_unequal                   |
-------------------------------------------------------------------------------------------------------
|          ndb_autoincrement_prefetch_sz           |                        32                        |
-------------------------------------------------------------------------------------------------------
|                  ndb_force_send                  |                        ON                        |
-------------------------------------------------------------------------------------------------------
|               ndb_use_exact_count                |                        ON                        |
-------------------------------------------------------------------------------------------------------
|               ndb_use_transactions               |                        ON                        |
-------------------------------------------------------------------------------------------------------
|               ndb_cache_check_time               |                        0                         |
-------------------------------------------------------------------------------------------------------
|                ndb_connectstring                 |                                                  |
-------------------------------------------------------------------------------------------------------
|                net_buffer_length                 |                      16384                       |
-------------------------------------------------------------------------------------------------------
|                 net_read_timeout                 |                       600                        |
-------------------------------------------------------------------------------------------------------
|                 net_retry_count                  |                        10                        |
-------------------------------------------------------------------------------------------------------
|                net_write_timeout                 |                      72000                       |
-------------------------------------------------------------------------------------------------------
|                       new                        |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                  old_passwords                   |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                 open_files_limit                 |                       1024                       |
-------------------------------------------------------------------------------------------------------
|              optimizer_prune_level               |                        1                         |
-------------------------------------------------------------------------------------------------------
|              optimizer_search_depth              |                        62                        |
-------------------------------------------------------------------------------------------------------
|                     pid_file                     |            /var/run/mysqld/mysqld.pid            |
-------------------------------------------------------------------------------------------------------
|                       port                       |                       3306                       |
-------------------------------------------------------------------------------------------------------
|               preload_buffer_size                |                      32768                       |
-------------------------------------------------------------------------------------------------------
|                    profiling                     |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|              profiling_history_size              |                        15                        |
-------------------------------------------------------------------------------------------------------
|                 protocol_version                 |                        10                        |
-------------------------------------------------------------------------------------------------------
|              query_alloc_block_size              |                       8192                       |
-------------------------------------------------------------------------------------------------------
|                query_cache_limit                 |                     1048576                      |
-------------------------------------------------------------------------------------------------------
|             query_cache_min_res_unit             |                       4096                       |
-------------------------------------------------------------------------------------------------------
|                 query_cache_size                 |                     16777216                     |
-------------------------------------------------------------------------------------------------------
|                 query_cache_type                 |                        ON                        |
-------------------------------------------------------------------------------------------------------
|           query_cache_wlock_invalidate           |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|               query_prealloc_size                |                       8192                       |
-------------------------------------------------------------------------------------------------------
|              range_alloc_block_size              |                       2048                       |
-------------------------------------------------------------------------------------------------------
|                 read_buffer_size                 |                      131072                      |
-------------------------------------------------------------------------------------------------------
|                    read_only                     |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|               read_rnd_buffer_size               |                      262144                      |
-------------------------------------------------------------------------------------------------------
|                 relay_log_purge                  |                        ON                        |
-------------------------------------------------------------------------------------------------------
|              relay_log_space_limit               |                        0                         |
-------------------------------------------------------------------------------------------------------
|                rpl_recovery_rank                 |                        0                         |
-------------------------------------------------------------------------------------------------------
|                   secure_auth                    |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                 secure_file_priv                 |                                                  |
-------------------------------------------------------------------------------------------------------
|                    server_id                     |                        0                         |
-------------------------------------------------------------------------------------------------------
|              skip_external_locking               |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                 skip_networking                  |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                skip_show_database                |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|            slave_compressed_protocol             |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                slave_load_tmpdir                 |                      /tmp/                       |
-------------------------------------------------------------------------------------------------------
|                slave_net_timeout                 |                       3600                       |
-------------------------------------------------------------------------------------------------------
|                slave_skip_errors                 |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|            slave_transaction_retries             |                        10                        |
-------------------------------------------------------------------------------------------------------
|                 slow_launch_time                 |                        2                         |
-------------------------------------------------------------------------------------------------------
|                      socket                      |           /var/run/mysqld/mysqld.sock            |
-------------------------------------------------------------------------------------------------------
|                 sort_buffer_size                 |                     2097144                      |
-------------------------------------------------------------------------------------------------------
|                 sql_big_selects                  |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                     sql_mode                     |                                                  |
-------------------------------------------------------------------------------------------------------
|                    sql_notes                     |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                   sql_warnings                   |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                      ssl_ca                      |                                                  |
-------------------------------------------------------------------------------------------------------
|                    ssl_capath                    |                                                  |
-------------------------------------------------------------------------------------------------------
|                     ssl_cert                     |                                                  |
-------------------------------------------------------------------------------------------------------
|                    ssl_cipher                    |                                                  |
-------------------------------------------------------------------------------------------------------
|                     ssl_key                      |                                                  |
-------------------------------------------------------------------------------------------------------
|                  storage_engine                  |                      MyISAM                      |
-------------------------------------------------------------------------------------------------------
|                   sync_binlog                    |                        0                         |
-------------------------------------------------------------------------------------------------------
|                     sync_frm                     |                        ON                        |
-------------------------------------------------------------------------------------------------------
|                 system_time_zone                 |                       PST                        |
-------------------------------------------------------------------------------------------------------
|                   table_cache                    |                        64                        |
-------------------------------------------------------------------------------------------------------
|             table_lock_wait_timeout              |                        50                        |
-------------------------------------------------------------------------------------------------------
|                    table_type                    |                      MyISAM                      |
-------------------------------------------------------------------------------------------------------
|                thread_cache_size                 |                        8                         |
-------------------------------------------------------------------------------------------------------
|                   thread_stack                   |                      131072                      |
-------------------------------------------------------------------------------------------------------
|                   time_format                    |                     %H:%i:%s                     |
-------------------------------------------------------------------------------------------------------
|                    time_zone                     |                      SYSTEM                      |
-------------------------------------------------------------------------------------------------------
|                  timed_mutexes                   |                       OFF                        |
-------------------------------------------------------------------------------------------------------
|                  tmp_table_size                  |                     33554432                     |
-------------------------------------------------------------------------------------------------------
|                      tmpdir                      |                       /tmp                       |
-------------------------------------------------------------------------------------------------------
|           transaction_alloc_block_size           |                       8192                       |
-------------------------------------------------------------------------------------------------------
|            transaction_prealloc_size             |                       4096                       |
-------------------------------------------------------------------------------------------------------
|                   tx_isolation                   |                 REPEATABLE-READ                  |
-------------------------------------------------------------------------------------------------------
|            updatable_views_with_limit            |                       YES                        |
-------------------------------------------------------------------------------------------------------
|                     version                      |                5.0.51a-3ubuntu5.8                |
-------------------------------------------------------------------------------------------------------
|                 version_comment                  |                     (Ubuntu)                     |
-------------------------------------------------------------------------------------------------------
|             version_compile_machine              |                      x86_64                      |
-------------------------------------------------------------------------------------------------------
|                version_compile_os                |                 debian-linux-gnu                 |
-------------------------------------------------------------------------------------------------------
|                   wait_timeout                   |                      28800                       |
-------------------------------------------------------------------------------------------------------

Posted: **Tue 07 Feb 2012 05:44**

Any thoughts? Help would really be appreciated. I'm stuck here.

Or is there an example of how to page through data?

Thanks!

Posted: **Tue 07 Feb 2012 16:10**

I've sent you a test project, please check that it is not blocked by your mail filter. If the sample runs successfully in your environment, please specify what should be changed in it to reproduce the issue, or send us your sample.

As for paging through a result set, you can use the Skip and Take extension methods for this. Please notice that using these methods lead to more complex (and possibly slower) queries.

Posted: **Tue 07 Feb 2012 20:16**

Thanks! Can you please resend the project? I have not received it - and it is not in my junk mail folder, etc..

Posted: **Tue 07 Feb 2012 20:34**

Nevermind - found it. Playing with it now to make it break like in my scenario. Thanks again.

Posted: **Sun 12 Feb 2012 22:28**

So no matter what I do, I cannot get your sample to break, even mimicking the structures I have. The only thing I can think of is it must be table size related, because as soon as I point your sample at the real database, using my objects, it croaks about 60 rows into the IQueryable Enumerator... I am currently at a loss as to how to proceed.

Posted: **Thu 16 Feb 2012 16:32**

Sorry for the delay. Since the problem cannot be reproduced with the table from the sample, but occurs in the actual application, it (the problem) may be connected with a peculiarity of this actual table or the data stored in it. Could you please specify the script of this table and some test data, so that we are able to analyze the situation in more details?

If the table description should not be disclosed, you can, e.g., rename the table/column names to something abstract, like 'table1', 'column1' etc.

Devart Forums

Lost connection to MySql server during query

Lost connection to MySql server during query