My self hosted forum (https://intfiction.org/) has the past couple of weeks started getting very slow, and it frequently has 502 and 503 errors. I’m on the stable branch, version 2026.1.5. Searching for those errors here hasn’t uncovered any likely causes: the forum builds and launches fine the server seems to have enough capacity (13.5GB disk space free, 1.6/1.9G RAM, 1.7/2.2G swap) Checking htop, the load average does look high though: 1.67, 1.55, 3.12. This process is sometimes using over 40% CPU: unicorn worker[0] -E production -c config/unicorn.conf.rb. In the forum logs I’m seeing a lot of errors like these: Job exception: execution expired net-smtp-0.5.1/lib/net/smtp.rb:663:in 'TCPSocket#initialize' net-smtp-0.5.1/lib/net/smtp.rb:663:in 'IO.open' net-smtp-0.5.1/lib/net/smtp.rb:663:in 'Net::SMTP#tcp_socket' net-smtp-0.5.1/lib/net/smtp.rb:672:in 'block in Net::SMTP#do_start' timeout-0.5.0/lib/timeout.rb:222:in 'block in Timeout.timeout' timeout-0.5.0/lib/timeout.rb:229:in 'Timeout.timeout' net-smtp-0.5.1/lib/net/smtp.rb:671:in 'Net::SMTP#do_start' net-smtp-0.5.1/lib/net/smtp.rb:642:in 'Net::SMTP#start' mail-2.9.0/lib/mail/network/delivery_methods/smtp.rb:154:in 'Mail::SMTP#start_smtp_session' mail-2.9.0/lib/mail/network/delivery_methods/smtp.rb:108:in 'Mail::SMTP#deliver!' mail-2.9.0/lib/mail/message.rb:269:in 'Mail::Message#deliver!' /usr/local/lib/ruby/3.4.0/delegate.rb:87:in 'Delegator#method_missing' /var/www/discourse/lib/email/sender.rb:296:in 'Email::Sender#send' /var/www/discourse/lib/email/processor.rb:151:in 'Email::Processor#handle_failure' /var/www/discourse/lib/email/processor.rb:31:in 'Email::Processor#process!' /var/www/discourse/lib/email/processor.rb:13:in 'Email::Processor.process!' /var/www/discourse/app/jobs/regular/process_email.rb:8:in 'Jobs::ProcessEmail#execute' /var/www/discourse/app/jobs/base.rb:318:in 'block (2 levels) in Jobs::Base#perform' rails_multisite-7.0.0/lib/rails_multisite/connection_management/null_instance.rb:49:in 'RailsMultisite::ConnectionManagement::NullInstance#with_connection' rails_multisite-7.0.0/lib/rails_multisite/connection_management.rb:17:in 'RailsMultisite::ConnectionManagement.with_connection' /var/www/discourse/app/jobs/base.rb:305:in 'block in Jobs::Base#perform' /var/www/discourse/app/jobs/base.rb:301:in 'Array#each' /var/www/discourse/app/jobs/base.rb:301:in 'Jobs::Base#perform' sidekiq-7.3.9/lib/sidekiq/processor.rb:220:in 'Sidekiq::Processor#execute_job' sidekiq-7.3.9/lib/sidekiq/processor.rb:185:in 'block (4 levels) in Sidekiq::Processor#process' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:180:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in 'block in Sidekiq::Middleware::Chain#traverse' /var/www/discourse/lib/sidekiq/suppress_user_email_errors.rb:6:in 'Sidekiq::SuppressUserEmailErrors#call' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in 'block in Sidekiq::Middleware::Chain#traverse' /var/www/discourse/lib/sidekiq/discourse_event.rb:6:in 'Sidekiq::DiscourseEvent#call' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in 'block in Sidekiq::Middleware::Chain#traverse' /var/www/discourse/lib/sidekiq/pausable.rb:131:in 'Sidekiq::Pausable#call' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in 'block in Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/job/interrupt_handler.rb:9:in 'Sidekiq::Job::InterruptHandler#call' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in 'block in Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:26:in 'Sidekiq::Metrics::ExecutionTracker#track' sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:134:in 'Sidekiq::Metrics::Middleware#call' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in 'Sidekiq::Middleware::Chain#traverse' sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:173:in 'Sidekiq::Middleware::Chain#invoke' sidekiq-7.3.9/lib/sidekiq/processor.rb:184:in 'block (3 levels) in Sidekiq::Processor#process' sidekiq-7.3.9/lib/sidekiq/processor.rb:145:in 'block (6 levels) in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/job_retry.rb:118:in 'Sidekiq::JobRetry#local' sidekiq-7.3.9/lib/sidekiq/processor.rb:144:in 'block (5 levels) in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/config.rb:39:in 'block in ' sidekiq-7.3.9/lib/sidekiq/processor.rb:139:in 'block (4 levels) in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/processor.rb:281:in 'Sidekiq::Processor#stats' sidekiq-7.3.9/lib/sidekiq/processor.rb:134:in 'block (3 levels) in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/job_logger.rb:15:in 'Sidekiq::JobLogger#call' sidekiq-7.3.9/lib/sidekiq/processor.rb:133:in 'block (2 levels) in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/job_retry.rb:85:in 'Sidekiq::JobRetry#global' sidekiq-7.3.9/lib/sidekiq/processor.rb:132:in 'block in Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/job_logger.rb:40:in 'Sidekiq::JobLogger#prepare' sidekiq-7.3.9/lib/sidekiq/processor.rb:131:in 'Sidekiq::Processor#dispatch' sidekiq-7.3.9/lib/sidekiq/processor.rb:183:in 'block (2 levels) in Sidekiq::Processor#process' sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in 'Thread.handle_interrupt' sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in 'block in Sidekiq::Processor#process' sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in 'Thread.handle_interrupt' sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in 'Sidekiq::Processor#process' sidekiq-7.3.9/lib/sidekiq/processor.rb:86:in 'Sidekiq::Processor#process_one' sidekiq-7.3.9/lib/sidekiq/processor.rb:76:in 'Sidekiq::Processor#run' sidekiq-7.3.9/lib/sidekiq/component.rb:10:in 'Sidekiq::Component#watchdog' sidekiq-7.3.9/lib/sidekiq/component.rb:19:in 'block in Sidekiq::Component#safe_thread' I’m also seeing a bunch of messages about Redis: Job exception: Connection timed out - user specified timeout: 1.0s (redis://localhost:6379) Your Redis network connection is performing extremely poorly. Last RTT readings were [403941, 62224, 151840, 1536008, 3440226], ideally these should be < 1000. Ensure Redis is running in the same AZ o But I don’t know if these are showing that Redis is the cause or just a symptom. I’ve just run ./launcher rebuild app, and it’s not any better. Any ideas for how to diagnose what is going wrong on this server?

Just noticed some more while watching top: postgres: 15/main: discourse discourse [local] idle used up to 90% CPU, and it’s doing so for over a minute. Edit: the forum was doing its daily backup, so I think that’s the cause of this one. I’m running the mail receiver on this server, and it seems to get hit by waves of spam: [image]

Those waves of incoming spam email are not going to help. But I agree - add RAM if you can. Double it.

Self hosted forum has frequent 502 and 503 errors

Product Support Self-hosting

NateDhaliwal (Nate Dhaliwal) July 5, 2026, 4:05am 2

I would suggest upping the RAM a bit more first, that could help.

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Self hosted forum has frequent 502 and 503 errors

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