Rebake fallisce: come diagnosticare e risolvere?

Hi,

After disabling the CDN on my forum, I ran rake posts:rebake.
It failed after a few dozen thousand rebake.

Searching for on of the error messages (“PQsocket() can’t get socket descriptor”) led me to Rake:rebake crashes with errors: PG::ConnectionBad: PQsocket - #8 by j127 where adding swap solved the issue.
I’m not sure the issue is the same tho, but I tried it, and rebaking still fail. It’s possible that it fails after more rebaking than before after adding swap but I didn’t write down how many rebakes it failed the first times.

What happens:

  1. It starts rebaking, and crashes after about 200000 posts out of 1.6 million.
    root@Unicyclist-app:/var/www/discourse# rake posts:rebake
    Rebaking post markdown for 'default'
       202930 / 1634878 ( 12.4%)
    Failed to rebake (topic_id: 196639, post_id: 1470519)
    PQconsumeInput() server closed the connection unexpectedly
            This probably means the server terminated abnormally
            before or while processing the request.
    
  2. After this message, this error is instantly shown for hundreds of subsequent posts :
       202931 / 1634878 ( 12.4%)
    Failed to rebake (topic_id: 196638, post_id: 1470518)
    PQsocket() can't get socket descriptor
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `async_exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/postgresql/database_statements.rb:167:in `perform_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:556:in `block (2 levels) in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1017:in `block in with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/concurrency/null_lock.rb:9:in `synchronize'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:986:in `with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:555:in `block in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/notifications/instrumenter.rb:58:in `instrument'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1137:in `log'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:554:in `raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:591:in `internal_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:547:in `internal_exec_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:693:in `select'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:73:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/query_cache.rb:262:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/querying.rb:68:in `_query_by_sql'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/querying.rb:53:in `block in find_by_sql'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_handling.rb:312:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/querying.rb:52:in `find_by_sql'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/statement_cache.rb:152:in `execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/core.rb:454:in `block in cached_find_by'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_handling.rb:312:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/core.rb:442:in `cached_find_by'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/core.rb:327:in `find_by'
    /var/www/discourse/lib/pretty_text/helpers.rb:20:in `avatar_template'
    /var/www/discourse/lib/pretty_text.rb:255:in `call'
    /var/www/discourse/lib/pretty_text.rb:255:in `eval'
    /var/www/discourse/lib/pretty_text.rb:255:in `block in markdown'
    /var/www/discourse/lib/pretty_text.rb:695:in `block in protect'
    /var/www/discourse/lib/pretty_text.rb:695:in `synchronize'
    /var/www/discourse/lib/pretty_text.rb:695:in `protect'
    /var/www/discourse/lib/pretty_text.rb:192:in `markdown'
    /var/www/discourse/lib/pretty_text.rb:318:in `cook'
    /var/www/discourse/app/models/post_analyzer.rb:30:in `cook'
    /var/www/discourse/app/models/post.rb:359:in `cook'
    /var/www/discourse/app/models/post.rb:836:in `rebake!'
    /var/www/discourse/lib/tasks/posts.rake:145:in `rebake_post'
    /var/www/discourse/lib/tasks/posts.rake:132:in `block (2 levels) in rebake_posts'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation/delegation.rb:101:in `each'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation/delegation.rb:101:in `each'
    /var/www/discourse/lib/tasks/posts.rake:131:in `block in rebake_posts'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/lib/tasks/posts.rake:126:in `rebake_posts'
    /var/www/discourse/lib/tasks/posts.rake:111:in `block in rebake_posts_all_sites'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:49:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:36:in `each_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management.rb:17:in `each_connection'
    /var/www/discourse/lib/tasks/posts.rake:111:in `rebake_posts_all_sites'
    /var/www/discourse/lib/tasks/posts.rake:7:in `block in <main>'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:281:in `block in execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:281:in `each'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:281:in `execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:219:in `block in invoke_with_call_chain'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:199:in `synchronize'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:199:in `invoke_with_call_chain'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/task.rb:188:in `invoke'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:188:in `invoke_task'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:138:in `block (2 levels) in top_level'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:138:in `each'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:138:in `block in top_level'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:147:in `run_with_threads'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:132:in `top_level'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:83:in `block in run'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:214:in `standard_exception_handling'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rake-13.3.1/lib/rake/application.rb:80:in `run'
    bin/rake:13:in `<top (required)>'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli/exec.rb:59:in `load'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli/exec.rb:59:in `kernel_load'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli/exec.rb:23:in `run'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli.rb:452:in `exec'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/vendor/thor/lib/thor/command.rb:28:in `run'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/vendor/thor/lib/thor/invocation.rb:127:in `invoke_command'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/vendor/thor/lib/thor.rb:538:in `dispatch'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli.rb:35:in `dispatch'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/vendor/thor/lib/thor/base.rb:584:in `start'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/cli.rb:29:in `start'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/exe/bundle:28:in `block in <top (required)>'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/lib/bundler/friendly_errors.rb:117:in `with_friendly_errors'
    /usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.6.4/exe/bundle:20:in `<top (required)>'
    /usr/local/bin/bundle:25:in `load'
    /usr/local/bin/bundle:25:in `<main>'
    
  3. Until it ends with this multiple times:
    Caused by:
    ActiveRecord::ConnectionNotEstablished: PQsocket() can't get socket descriptor (ActiveRecord::ConnectionNotEstablished)
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `async_exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/postgresql/database_statements.rb:167:in `perform_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:556:in `block (2 levels) in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1017:in `block in with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/concurrency/null_lock.rb:9:in `synchronize'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:986:in `with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:555:in `block in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/notifications/instrumenter.rb:58:in `instrument'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1137:in `log'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:554:in `raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:591:in `internal_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:547:in `internal_exec_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:693:in `select'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:73:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/query_cache.rb:262:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/querying.rb:68:in `_query_by_sql'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1459:in `block (2 levels) in exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_handling.rb:312:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1458:in `block in exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1480:in `skip_query_cache_if_necessary'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1442:in `exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1420:in `block in exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1480:in `skip_query_cache_if_necessary'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1414:in `exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/goldiloader-6.0.0/lib/goldiloader/active_record_patches.rb:40:in `exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1191:in `load'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:353:in `records'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation/delegation.rb:101:in `each'
    /var/www/discourse/lib/tasks/posts.rake:131:in `block in rebake_posts'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/lib/tasks/posts.rake:126:in `rebake_posts'
    /var/www/discourse/lib/tasks/posts.rake:111:in `block in rebake_posts_all_sites'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:49:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:36:in `each_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management.rb:17:in `each_connection'
    /var/www/discourse/lib/tasks/posts.rake:111:in `rebake_posts_all_sites'
    /var/www/discourse/lib/tasks/posts.rake:7:in `block in <main>'
    /usr/local/bin/bundle:25:in `load'
    /usr/local/bin/bundle:25:in `<main>'
    
    Caused by:
    PG::ConnectionBad: PQsocket() can't get socket descriptor (PG::ConnectionBad)
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.1/lib/patches/db/pg/alias_method.rb:109:in `async_exec'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/postgresql/database_statements.rb:167:in `perform_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:556:in `block (2 levels) in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1017:in `block in with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/concurrency/null_lock.rb:9:in `synchronize'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:986:in `with_raw_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:555:in `block in raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/notifications/instrumenter.rb:58:in `instrument'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract_adapter.rb:1137:in `log'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:554:in `raw_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:591:in `internal_execute'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:547:in `internal_exec_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:693:in `select'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/database_statements.rb:73:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/query_cache.rb:262:in `select_all'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/querying.rb:68:in `_query_by_sql'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1459:in `block (2 levels) in exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/connection_handling.rb:312:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1458:in `block in exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1480:in `skip_query_cache_if_necessary'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1442:in `exec_main_query'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1420:in `block in exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1480:in `skip_query_cache_if_necessary'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1414:in `exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/goldiloader-6.0.0/lib/goldiloader/active_record_patches.rb:40:in `exec_queries'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:1191:in `load'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation.rb:353:in `records'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activerecord-8.0.4/lib/active_record/relation/delegation.rb:101:in `each'
    /var/www/discourse/lib/tasks/posts.rake:131:in `block in rebake_posts'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-8.0.4/lib/active_support/core_ext/range/each.rb:14:in `step'
    /var/www/discourse/lib/tasks/posts.rake:126:in `rebake_posts'
    /var/www/discourse/lib/tasks/posts.rake:111:in `block in rebake_posts_all_sites'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:49:in `with_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:36:in `each_connection'
    /var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-7.0.0/lib/rails_multisite/connection_management.rb:17:in `each_connection'
    /var/www/discourse/lib/tasks/posts.rake:111:in `rebake_posts_all_sites'
    /var/www/discourse/lib/tasks/posts.rake:7:in `block in <main>'
    /usr/local/bin/bundle:25:in `load'
    /usr/local/bin/bundle:25:in `<main>'
    Tasks: TOP => posts:rebake
    (See full trace by running task with --trace)
    root@Unicyclist-app:/var/www/discourse#
    

Here’s the output of free -h during the rebake (the values are roughly the same at any time during the rebake):

               total        used        free      shared  buff/cache   available
Mem:           7.6Gi       4.6Gi       231Mi       2.1Gi       2.8Gi       709Mi
Swap:          2.0Gi       1.8Gi       194Mi

I also have a lot of free space (I didn’t the first times, but freed space just in case, and it didn’t change anything).

I have rebaked all posts on this forum a few times over the last years and I never faced any issues. The forum hasn’t grown much, the server’s specs are the same as before.

Sto ancora cercando aiuto per questo :face_with_tongue:

Ho aumentato la dimensione dello swap da 2 a 4 GB e il ribake ha funzionato.

Quindi, immagino che si trattasse di memoria, anche se sono un po’ sorpreso da quanta ne richieda (8 GB di RAM + 4 GB di swap), specialmente perché i ribake precedenti non avevano problemi senza swap e con la stessa quantità di RAM.

Cosa dovrei fare se voglio monitorare l’utilizzo della RAM e verificare eventuali problemi? Quale metrica dovrebbe essere importante per stimare i requisiti di memoria? Pagine viste al giorno (5000-8000 + picchi di bot una o due volte al mese)? Dimensione del database (23 GB)? :person_shrugging: :face_with_raised_eyebrow:

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L’utilizzo della memoria è molto maggiore durante una ricostruzione rispetto al normale funzionamento. Sembra che anche il “rebaking” (ri-cottura/ricalcolo) comporti una grande richiesta. Se è così, qualsiasi tipo di monitoraggio regolare non aggiungerebbe molto valore: il monitoraggio sarebbe necessario durante quei picchi, che fortunatamente avvengono quando l’amministratore esegue un’azione specifica.

Quando operavo su una configurazione macchina più piccola e marginale, tenevo aperta una seconda finestra del terminale, connessa via ssh al mio server ed eseguivo
vmstat 5
che fornisce una registrazione dell’utilizzo della memoria mentre fluttua. Osserva la colonna swpd e confrontala con lo spazio di swap configurato. Comunemente il fallimento avviene improvvisamente, non gradualmente, quindi anche osservare le tendenze a breve termine non è di grande aiuto.

Se hai spazio su disco, non c’è alcun danno nell’avere molto swap - la metà della RAM, o anche quanto la RAM. È lì in questo caso per far fronte ai picchi. Non vuoi vedere attività di swapping/paging durante l’uso normale. Ancora una volta, si può usare vmstat 5 5 per ottenere un’istantanea a breve termine dell’attività di paging (nelle colonne si e so)

Ecco un esempio:

# vmstat 5 5
procs -----------memory----------   ---swap--  -----io---- -system--  ------cpu-----
 r  b   swpd   free   buff  cache     si    so    bi    bo   in    cs us sy id wa st
 3  0 1392140  61200  11632  76432    41    32   117    93    0     1  2  1 97  0  0
 1  1 1467220  63416    324  67284  8786 20499 13178 20567 2539  8924 77 13  0 10  0
 0  2 1593340  57916   1096  53832 24262 46868 29986 46889 5377 18534 44 22  0 34  0
 4  0 1155632 120680   2772  86280 39111 35424 54768 37824 6987 25174 38 27  0 35  0
 3  0 1102988  74096   2852  85276 11261   246 12610   271 1879  6365 86  6  0  8  0

Si vede che la colonna swpd ha raggiunto un picco di oltre 1,5G, rispetto ai miei 2,0G configurati. Si vede che l’attività di swapout (so) ha raggiunto il picco nella stessa finestra di 5 secondi, e lo swapin (si) ha raggiunto il picco nella finestra successiva.

(Modifica: vedo che avevo configurato 2,0G di swap perché in precedenza avevo eseguito free:

# free
              total        used        free      shared  buff/cache   available
Mem:        1009140      696504       78544       51784      234092      118436
Swap:       2097144      154628     1942516

si vede anche che all’epoca riuscivo a far funzionare discourse con solo 1G di RAM.)

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Interessante. Sono a corto di spazio su disco da un po’. Attualmente sto cercando di ridimensionare ad altri piani (creerò un argomento a riguardo) e vedere come si confrontano le prestazioni, ma invece di fare questo, pensi che sarebbe un’idea migliore - sulla carta, almeno - mantenere il mio piano, spostare i miei backup su un volume aggiuntivo economico[1], e aggiungere diversi GB di swap?


  1. Beh, devo vedere quanta differenza c’è tra l’aggiungere un volume o il cambiare il mio piano con un altro che offre anche più spazio su disco) ↩︎

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Questo è un compromesso possibile. Una delle prime cose che ho fatto è stata limitare il numero (e regolare la frequenza) dei backup. Non sono ancora passato allo storage a blocchi per i backup o i caricamenti, ma potrebbe essere un vantaggio, se estende la vita utile di una configurazione con RAM limitata.

(Un’altra cosa che ho fatto, verso la fine del mio periodo sulle macchine con la configurazione più piccola, è stata ridimensionare temporaneamente a un’istanza con più RAM solo per il tempo necessario a eseguire un aggiornamento, e poi tornare al ridimensionamento precedente. È costato solo pochi centesimi, anche se l’istanza più grande potrebbe costare il doppio al mese. Ma richiede un po’ di inattività, e un po’ di tempo e attenzione. E richiede che il tuo provider abbia una macchina più grande con la stessa capacità del disco - il passaggio a una configurazione con disco più grande è solitamente una strada a senso unico.)

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Il mio provider consente l’aumento di scala mantenendo lo stesso spazio su disco, il che consente la riduzione di scala se necessario :slight_smile:

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