Redis EXECABORT Transaction discarded because of previous errors. (Redis::CommandError)

Question

I'm trying to push some jobs onto a Sidekiq queue, which up until now, worked just fine. The error only appears in production.

Stack trace:

2013-12-13T20:35:04Z 22616 TID-amwho INFO: Sidekiq client with redis options {}
/home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis/pipeline.rb:79:in `finish': EXECABORT Transaction discarded because of previous errors. (Redis::CommandError)
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis/client.rb:121:in `block in call_pipeline'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis/client.rb:245:in `with_reconnect'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis/client.rb:119:in `call_pipeline'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis.rb:2093:in `block in multi'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis.rb:36:in `block in synchronize'
    from /home/avishai/.rvm/rubies/ruby-1.9.3-p429/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis.rb:36:in `synchronize'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/redis-3.0.6/lib/redis.rb:2085:in `multi'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/client.rb:159:in `block in raw_push'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/connection_pool-1.2.0/lib/connection_pool.rb:55:in `with'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq.rb:67:in `redis'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/client.rb:150:in `raw_push'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/client.rb:50:in `push'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/client.rb:98:in `push'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/worker.rb:83:in `client_push'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/sidekiq-2.17.0/lib/sidekiq/worker.rb:40:in `perform_async'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/listings_feed_parser.rb:79:in `send_to_sidekiq'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/listings_feed_parser.rb:74:in `enqueue'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:235:in `block in parse'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:24:in `block (2 levels) in each_listing'
    from /home/avishai/apps/XXX/shared/bundle/ruby/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/reader.rb:107:in `each'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:22:in `block in each_listing'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:21:in `open'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:21:in `each_listing'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/parsers/listings.rb:36:in `parse'
    from /home/avishai/apps/XXX/releases/20131213194843/lib/listings_feed/listings_feed.rb:153:in `process!'
    from run_feed.rb:74:in `block in <main>'
    from run_feed.rb:71:in `each'
    from run_feed.rb:71:in `<main>'

Answer 1

I resolved this by doing a FLUSHALL, which cleared out all the data from the redis instance. It appears that somewhere along the way the data got corrupted, and that fixed it.

Answer 2

Another possible reason is a broken master-slave replication. For example with min-slaves-to-write configuration option set:

127.0.0.1:6379> set foo 1
(error) NOREPLICAS Not enough good slaves to write.

To temporarily resolve just execute:

CONFIG SET min-slaves-to-write 0

Answer 3

I also encountered this error when hitting maxmemory on that redis instance.

You can test it on your dev box by setting maxmemory (ie.. in /usr/local/etc/redis.conf) to sthg small e.g.

 maxmemory 3MB

Then fill up your redis with a bunch of data, start Sidekiq, and watch the fireworks

    2014-02-03T14:32:30Z 59365 TID-ov2cb18yw WARN: {"retry"=>true, "queue"=>"default", "backtrace"=>true, "class"=>"MailWorker", "args"=>["Profile::Created", 868], "jid"=>"d7b0589736818c2ffcd58c90", "enqueued_at"=>1391437950.4245608}
    2014-02-03T14:32:30Z 59365 TID-ov2cb18yw WARN: EXECABORT Transaction discarded because of previous errors.
    2014-02-03T14:32:30Z 59365 TID-ov2cb18yw WARN: /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis/pipeline.rb:76:in `finish'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis/client.rb:121:in `block in call_pipeline'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis/client.rb:243:in `with_reconnect'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis/client.rb:119:in `call_pipeline'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis.rb:2077:in `block in multi'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis.rb:36:in `block in synchronize'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis.rb:36:in `synchronize'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-3.0.4/lib/redis.rb:2069:in `multi'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-namespace-1.3.1/lib/redis/namespace.rb:337:in `namespaced_block'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/redis-namespace-1.3.1/lib/redis/namespace.rb:224:in `multi'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/sidekiq-2.13.1/lib/sidekiq/processor.rb:93:in `block in stats'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/connection_pool-1.1.0/lib/connection_pool.rb:49:in `with'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/sidekiq-2.13.1/lib/sidekiq.rb:67:in `redis'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/sidekiq-2.13.1/lib/sidekiq/util.rb:25:in `redis'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/sidekiq-2.13.1/lib/sidekiq/processor.rb:92:in `stats'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/sidekiq-2.13.1/lib/sidekiq/processor.rb:46:in `block in process'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/calls.rb:25:in `call'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/calls.rb:25:in `public_send'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/calls.rb:25:in `dispatch'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/calls.rb:67:in `dispatch'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/future.rb:15:in `block in new'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/internal_pool.rb:59:in `call'
    /usr/local/opt/rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/celluloid-0.14.1/lib/celluloid/internal_pool.rb:59:in `block in create'