Job exception error

AI-generated summary

philh reports that after migrating Discourse instances from DigitalOcean to Hetzner and applying Ubuntu USG hardening, three of seven sites experience daily outages lasting 5–15 minutes. The issue begins with a Job exception: Waited 1.0 seconds error, followed by Failed to warm up pretty text: terminated messages, indicating a potential Redis or V8 JavaScript processing issue. Despite upgrading to 4GB RAM and 3 CPUs, the problem persists. philh suspects the CIS hardening may conflict with Discourse, as reinstalling on a fresh server without the audit/fix work resolves the issue. They conclude that while hardening is valuable, overly aggressive security configurations may interfere with Discourse’s operation, and a simpler, updated approach may be preferable.

I have a handful of Discourse instances that ran for a very long tome without issues. Recently I moved to Hetzner from DO. As part of the move I finally initiated monitoring, using Uptime for now. I hardened the servers using Ubuntu USG.

Three of the 7 instances have routinely going offline for 5 to 15 minutes around the same time daily. Perhaps this was occurring on DO but without monitoring who knows.

All site are running the same cast of Official plugins.
Suspecting a memory issue I upgraded one instance from 2 CPU 2GB RAM to 3 CPU with 4GB RAM
Did not change db_shared_buffers: “256MB”
Did not change UNICORN_WORKERS: 4

The increased performance seems to have helps but should I need so much resources on a very quiet site?

Any thoughts or suggestions would be appreciated.

The incident sequence always starts with a Job exception error

Message (4 copies reported)

Job exception: Waited 1.0 seconds

Backtrace

/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/buffered_io.rb:214:in `block in fill_buffer'
<internal:kernel>:187:in `loop'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/buffered_io.rb:197:in `fill_buffer'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/buffered_io.rb:187:in `ensure_remaining'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/buffered_io.rb:152:in `getbyte'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/resp3.rb:113:in `parse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection/resp3.rb:50:in `load'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/ruby_connection.rb:96:in `read'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/connection_mixin.rb:31:in `call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client.rb:316:in `block (2 levels) in call_v'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client/middlewares.rb:16:in `call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client.rb:315:in `block in call_v'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client.rb:721:in `ensure_connected'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-client-0.25.0/lib/redis_client.rb:314:in `call_v'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-5.4.0/lib/redis/client.rb:90:in `call_v'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rack-mini-profiler-4.0.0/lib/mini_profiler/profiling_methods.rb:90:in `block in profile_method'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-5.4.0/lib/redis.rb:152:in `block in send_command'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-5.4.0/lib/redis.rb:151:in `synchronize'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-5.4.0/lib/redis.rb:151:in `send_command'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/redis-5.4.0/lib/redis/commands/strings.rb:191:in `get'
/var/www/discourse/lib/discourse_redis.rb:144:in `public_send'
/var/www/discourse/lib/discourse_redis.rb:144:in `block (3 levels) in <class:DiscourseRedis>'
/var/www/discourse/lib/discourse_redis.rb:29:in `ignore_readonly'
/var/www/discourse/lib/discourse_redis.rb:144:in `block (2 levels) in <class:DiscourseRedis>'
/var/www/discourse/lib/sidekiq/pausable.rb:19:in `paused?'
/var/www/discourse/lib/sidekiq/pausable.rb:105:in `paused?'
/var/www/discourse/config/initializers/100-sidekiq.rb:98:in `block (3 levels) in <main>'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/mini_scheduler-0.18.0/lib/mini_scheduler.rb:74:in `block (2 levels) in start'

Followed soon after with something like:

Failed to warm up pretty text: terminated /var/www/discourse/lib/discourse_js_processor.rb:89:in `call' /var/www/discourse/lib/discourse_js_processor.rb:89:in `block in v8_call' /var/www/discourse/lib
Message (2 copies reported)

Failed to warm up pretty text: terminated
/var/www/discourse/lib/discourse_js_processor.rb:89:in `call'
/var/www/discourse/lib/discourse_js_processor.rb:89:in `block in v8_call'
/var/www/discourse/lib/discourse_js_processor.rb:88:in `synchronize'
/var/www/discourse/lib/discourse_js_processor.rb:88:in `v8_call'
/var/www/discourse/lib/discourse_js_processor.rb:113:in `perform'
/var/www/discourse/lib/pretty_text.rb:34:in `apply_es6_file'
/var/www/discourse/lib/pretty_text.rb:41:in `block in ctx_load_directory'
/var/www/discourse/lib/pretty_text.rb:39:in `each'
/var/www/discourse/lib/pretty_text.rb:39:in `ctx_load_directory'
/var/www/discourse/lib/pretty_text.rb:81:in `create_es6_context'
/var/www/discourse/lib/pretty_text.rb:135:in `block in v8'
/var/www/discourse/lib/pretty_text.rb:133:in `synchronize'
/var/www/discourse/lib/pretty_text.rb:133:in `v8'
/var/www/discourse/lib/pretty_text.rb:176:in `block in markdown'
/var/www/discourse/lib/pretty_text.rb:678:in `block in protect'
/var/www/discourse/lib/pretty_text.rb:678:in `synchronize'
/var/www/discourse/lib/pretty_text.rb:678:in `protect'
/var/www/discourse/lib/pretty_text.rb:175:in `markdown'
/var/www/discourse/lib/pretty_text.rb:301:in `cook'
/var/www/discourse/lib/discourse.rb:960:in `after_fork'
config/unicorn.conf.rb:197:in `block in reload'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:684:in `init_worker_process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:721:in `worker_loop'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:561:in `maintain_worker_count'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:294:in `join'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/bin/unicorn:128:in `<top (required)>'
/var/w...

Backtrace

/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/broadcast_logger.rb:134:in `block in error'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/broadcast_logger.rb:231:in `block in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/broadcast_logger.rb:231:in `each'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/broadcast_logger.rb:231:in `dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/broadcast_logger.rb:134:in `error'
/var/www/discourse/lib/discourse.rb:962:in `rescue in after_fork'
/var/www/discourse/lib/discourse.rb:958:in `after_fork'
config/unicorn.conf.rb:197:in `block in reload'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:684:in `init_worker_process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:721:in `worker_loop'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:561:in `maintain_worker_count'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:294:in `join'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/unicorn-6.1.0/bin/unicorn:128:in `<top (required)>'
/var/www/discourse/vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `load'
/var/www/discourse/vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `<main>'
`
``

So once again I am reminded of why paying the pros is often a good thing. This server hardening stuff is not easy. Still working on learning more but for now reinstalling discourse on fresh server without the cis_level1_server audit and fix work returns the sites to the usual error free running of Discourse.
Out of the box cis_level1_server tailoringfile.xml does not play well with Ghost as well although I was able to get my Mailcow working with the audit/fix methods.

Simple hardening with appropriate and frequent updates is probably good enough.