I encountered a problem like this and thought I should share my findings here in case it might help anyone else who experiences it.
In my case, the account merge operation hung forever with the “Merge progress” dialog cycling back and forth between the “Changing post ownership…” and “Updating username…” messages.
From looking at the staff action logs (/admin/logs/staff_action_logs),
I could see that, although the ownership of many posts was transferred
immediately after I triggered the merge, there were no additional actions, proving that the operation was truly hung instead of only taking a very long time to work through all the posts.
When I checked the error logs (/logs/), I could see that a “Job exception: topic” error was being produced periodically, with backtrace:
/var/www/discourse/app/services/post_owner_changer.rb:12:in `block in
initialize'
/var/www/discourse/app/services/post_owner_changer.rb:11:in `each'
/var/www/discourse/app/services/post_owner_changer.rb:11:in `initialize'
/var/www/discourse/app/services/user_merger.rb:84:in `new'
/var/www/discourse/app/services/user_merger.rb:84:in `change_post_owner'
/var/www/discourse/app/services/user_merger.rb:72:in `block in move_posts'
/var/www/discourse/app/services/user_merger.rb:70:in `each'
/var/www/discourse/app/services/user_merger.rb:70:in `move_posts'
/var/www/discourse/app/services/user_merger.rb:14:in `merge!'
/var/www/discourse/app/jobs/regular/merge_user.rb:15:in `execute'
/var/www/discourse/app/jobs/base.rb:316:in `block (2 levels) in perform'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-6.1.0/lib/rails_multisite/connection_management/null_instance.rb:49:in
`with_connection'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/rails_multisite-6.1.0/lib/rails_multisite/connection_management.rb:21:in
`with_connection'
/var/www/discourse/app/jobs/base.rb:303:in `block in perform'
/var/www/discourse/app/jobs/base.rb:299:in `each'
/var/www/discourse/app/jobs/base.rb:299:in `perform'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:220:in
`execute_job'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:185:in
`block (4 levels) in process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:180:in
`traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in
`block in traverse'
/var/www/discourse/lib/sidekiq/discourse_event.rb:6:in `call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in
`traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in
`block in traverse'
/var/www/discourse/lib/sidekiq/pausable.rb:131:in `call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in
`traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in
`block in traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job/interrupt_handler.rb:9:in
`call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in
`traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:183:in
`block in traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:26:in
`track'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/metrics/tracking.rb:134:in
`call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:182:in
`traverse'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/middleware/chain.rb:173:in
`invoke'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:184:in
`block (3 levels) in process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:145:in
`block (6 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_retry.rb:118:in
`local'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:144:in
`block (5 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/config.rb:39:in
`block in <class:Config>'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:139:in
`block (4 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:281:in
`stats'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:134:in
`block (3 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_logger.rb:15:in
`call'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:133:in
`block (2 levels) in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_retry.rb:85:in
`global'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:132:in
`block in dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/job_logger.rb:40:in
`prepare'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:131:in
`dispatch'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:183:in
`block (2 levels) in process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in
`handle_interrupt'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:182:in
`block in process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in
`handle_interrupt'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:181:in
`process'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:86:in
`process_one'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/processor.rb:76:in
`run'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/component.rb:10:in
`watchdog'
/var/www/discourse/vendor/bundle/ruby/3.3.0/gems/sidekiq-7.3.9/lib/sidekiq/component.rb:19:in
`block in safe_thread'
and env like this:
hostname [...]
process_id 701
application_version 3146142c2ed2c880d53b2f8c136af9f46df99b59
current_db default
current_hostname forum.arduino.cc
job Jobs::MergeUser
problem_db default
time 8:15 am
opts
user_id 42
target_user_id 123
current_user_id 456
current_site_id default
I finally determined that the hang was caused by the “from” user account having “orphaned” posts. By “orphaned”, I mean that there was a database entry for the post, but no entry for the topic associated with that post.
You can check for the presence of “orphan posts” in a given user’s account by running this Data Explorer query:
-- [params]
-- integer :user_id
SELECT
posts.id,
posts.topic_id
FROM
posts
WHERE
posts.user_id = :user_id
AND posts.topic_id NOT IN (
SELECT
topics.id
FROM
topics
)
After the orphan posts were removed from the database (thanks to the assistance from the Discourse team since we are using a hosting plan), I was able to successfully accomplish the account merge operation.