# MySQL Error inserting blob **URL:** \ **Category:** Rails\ **Created:** [December 10, 2008, 9:04am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290 "2008-12-10T09:04:25Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 9:04am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/1 "2008-12-10T09:04:25Z")
Hi, I’m trying to insert a blob into a MySQL database with a Rails app. I’m getting the error: ActiveRecord::StatementInvalid (Mysql::Error: MySQL server has gone away: INSERT INTO `index_entries` (`legal_case_id`,`document_id`,`sword`,`word_count`,`map_data`,`created_at`,`updated_at`) VALUES (3,1368,‘f’,208720,‘\0\0…blob data…\0Å’1\0 Å’1\0’,‘2008-12-10 05:17:29’,‘2008-12-10 05:17:29’) ON DUPLICATE KEY UPDATE `index_entries`.`updated_at`=VALUES(`updated_at`)): I believe the blob itself should be about 820K long. Cutting it back to 800K, it works alright. But I’ve checked my MySQL config, and it claims that max\_packet\_size=1M. I’ve also tried setting it to 32M, and that didn’t make any difference. I’ve also tried replacing the data with a sequence “01010101…” of the same length, and the same thing occurs: at 800K it works, but the same error occurs at 820K. Does anyone know what’s going on? Any help most appreciated! Here is the stack trace: ``` C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract_adapter.rb:188:in ``` `log' C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/mysql_adapter.rb:309:in`execute’ C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active\_record/connection\_adapters/abstract/database\_statements.rb:171:in `insert_sql' C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/mysql_adapter.rb:319:in`insert\_sql’ C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active\_record/connection\_adapters/abstract/database\_statements.rb:44:in `insert_without_query_dirty' C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/query_cache.rb:18:in`insert’ C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/adapters/abstract\_adapter.rb:46:in `insert_many' C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/adapters/abstract_adapter.rb:43:in`each’ C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/adapters/abstract\_adapter.rb:43:in `insert_many' C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/import.rb:282:in`import\_without\_validations\_or\_callbacks’ C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/import.rb:243:in `import_with_validations' C:/Ruby/lib/ruby/gems/1.8/gems/ar-extensions-0.8.0/lib/ar-extensions/import.rb:202:in`import’ /app/models/document.rb:150:in `index' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/buffered_logger.rb:25:in`silence’ /app/models/document.rb:149:in `index' /app/models/document.rb:19:in`integrate\_import\_record’ /app/models/import\_set.rb:44:in `integrate' /app/models/import_set.rb:33:in`each’ /app/models/import\_set.rb:33:in `integrate' /app/controllers/import_sets_controller.rb:47:in`integrate’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/base.rb:1253:in `send' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/base.rb:1253:in`perform\_action\_without\_filters’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/filters.rb:617:in `call_filters' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/filters.rb:610:in`perform\_action\_without\_benchmark’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/benchmarking.rb:68:in `perform_action_without_rescue' C:/Ruby/lib/ruby/1.8/benchmark.rb:293:in`measure’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/benchmarking.rb:68:in `perform_action_without_rescue' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/rescue.rb:136:in`perform\_action\_without\_caching’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/caching/sql\_cache.rb:13:in `perform_action' C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in`cache’ C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active\_record/query\_cache.rb:8:in `cache' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/caching/sql_cache.rb:12:in`perform\_action’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/base.rb:524:in `send' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/base.rb:524:in`process\_without\_filters’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/filters.rb:606:in `process_without_session_management_support' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/session_management.rb:134:in`process’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/base.rb:392:in `process' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:183:in`handle\_request’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/dispatcher.rb:110:in `dispatch_unlocked' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:123:in`dispatch’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/dispatcher.rb:122:in `synchronize' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:122:in`dispatch’ C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action\_controller/dispatcher.rb:132:in `dispatch_cgi' C:/Ruby/lib/ruby/gems/1.8/gems/actionpack-2.2.2/lib/action_controller/dispatcher.rb:39:in`dispatch’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/bin/…/lib/mongrel/rails.rb:76:in `process' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/bin/../lib/mongrel/rails.rb:74:in`synchronize’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/bin/…/lib/mongrel/rails.rb:74:in `process' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:159:in`process\_client’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:158:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:158:in`process\_client’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:285:in `run' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:285:in`initialize’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:285:in `new' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:285:in`run’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:268:in `initialize' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:268:in`new’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel.rb:268:in `run' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel/configurator.rb:282:in`run’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel/configurator.rb:281:in `each' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel/configurator.rb:281:in`run’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/bin/mongrel\_rails:128:in `run' C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/lib/mongrel/command.rb:212:in`run’ C:/Ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.5-x86-mswin32-60/bin/mongrel\_rails:281 C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active\_support/dependencies.rb:142:in `load_without_new_constant_marking' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:142:in`load’ C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active\_support/dependencies.rb:521:in `new_constants_in' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:142:in`load’ C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/commands/servers/mongrel.rb:64 C:/Ruby/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in `gem_original_require' C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`require’ C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active\_support/dependencies.rb:153:in `require' C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:521:in`new\_constants\_in’ C:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active\_support/dependencies.rb:153:in `require' C:/Ruby/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/commands/server.rb:49 C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in`gem\_original\_require’ C:/Ruby/lib/ruby/site\_ruby/1.8/rubygems/custom\_require.rb:27:in `require’ script/server:6 - Farmer ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 9:36am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/2 "2008-12-10T09:36:22Z")
Actually, the variable in my my.ini file is max\_allowed\_packet, not max\_packet\_size. ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 9:48am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/3 "2008-12-10T09:48:44Z")
we have had the same problem and it turned out to be the size of the column in mysql whenever we create a blog column we go through and change the type to LONGBLOB using the following in the migration. execute “ALTER TABLE pgcs CHANGE pgc pgc LONGBLOB;” Simon On Wed, 10 Dec 2008 17:04:25 +0900, Farmer Schlutzenberg ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 10:02am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/4 "2008-12-10T10:02:32Z")
Hi Simon, I have it set on MEDIUMBLOB, which the MySQL documentation says has a limit of 2^24 bytes, so well above 820K. It was previously on BLOB, and I was getting a different error (something like “data too big for column”). I just used :limit =\> size\_limit as a condition in a rails migration, and this changed the column type from BLOB to MEDIUMBLOB. Thanks tho. ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 10:13am UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/5 "2008-12-10T10:13:58Z")
I just know that when we had that ‘mysql has gone away’ error, the mysql logs had something like ‘value too large for col’ etc… But if that isn’t your problem, then I have nothing else to offer ☹ On Wed, 10 Dec 2008 18:02:32 +0900, Farmer Schlutzenberg ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 12:03pm UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/6 "2008-12-10T12:03:18Z")
I’ve now worked it out. I eventually decided to restart my computer on the off chance that MySQL wasn’t actually reconfiguring after I set max\_allowed\_packet (even though it seemed this shouldn’t actually affect things since I was only changing from 1M to 32M, and my query seems to be less than 1M). This fixed the problem. It seems odd to me that I should need to restart my computer to get MySQL to recognise the change - I did restart my server after the config change to 32M, so I expected the connection made to MySQL to use the 32M packet size. If anyone knows how to configure MySQL to not require computer restarts (this is in Vista), that would be good to know. Even stranger is that with a supposed limit of 1M, the following code - puts blobstring.class puts blobstring.length Record.new(:field\_1 =\> integer\_1, :field\_2 =\> integer\_2, :field\_3 =\> word, :field\_4 =\> integer\_4, :blob\_field =\> blobstring).save outputs: String 834880 and causes a “MySQL has gone away” error, on response to the MySQL insert command caused by the “save” call above, yet with max\_allowed\_packet=32M, it works fine. Maybe there are is more than just the query string itself contributing to the 1 megabyte? - Farmer - Farmer ---
**Author:** ![farmerss](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@farmerss](https://www.ruby-forum.com/u/farmerss)\ **Post date:** [December 10, 2008, 12:05pm UTC](https://www.ruby-forum.com/t/mysql-error-inserting-blob/155290/7 "2008-12-10T12:05:13Z")
And, in field\_3 it was just word=“f”, so that shouldn’t have added too much. And, as I mentioned earlier, cutting the blob size down to 800K also made it work OK.