恢复失败,ALTER TABLE 挂起,超时

I had a disk failure on a discourse server, and I’m trying to restore a backup from S3 onto an AWS EC2 t2.small instance. Consistently getting the below error.

Using this flow:

git clone https://github.com/discourse/discourse_docker /var/discourse

I’m using this app.yml

./launcher bootstrap app
./launcher start app

Then I scp the backup, ./launcher enter app, discourse enable_restore discourse restore <the file>.

Then this happens, beginning truncated:

14
(1 row)
setval
--------
1
(1 row)
setval
--------
1
(1 row)
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
ALTER TABLE
 #<Thread:0x0000562604925448 /var/www/discourse/lib/sidekiq/pausable.rb:79 run> terminated with exception (report_on_exception is true):
Traceback (most recent call last):
        33: from /var/www/discourse/lib/sidekiq/pausable.rb:83:in `block (2 levels) in extend_lease_thread'
        32: from /var/www/discourse/lib/sidekiq/pausable.rb:83:in `synchronize'
        31: from /var/www/discourse/lib/sidekiq/pausable.rb:84:in `block (3 levels) in extend_lease_thread'
        30: from /usr/local/lib/ruby/2.7.0/set.rb:328:in `each'
        29: from /usr/local/lib/ruby/2.7.0/set.rb:328:in `each_key'
        28: from /var/www/discourse/lib/sidekiq/pausable.rb:85:in `block (4 levels) in extend_lease_thread'
        27: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rails_multisite-2.5.0/lib/rails_multisite/connection_management.rb:76:in `with_connection'
        26: from /var/www/discourse/lib/sidekiq/pausable.rb:86:in `block (5 levels) in extend_lease_thread'
        25: from /var/www/discourse/lib/discourse_redis.rb:59:in `block (2 levels) in <class:DiscourseRedis>'
        24: from /var/www/discourse/lib/discourse_redis.rb:29:in `ignore_readonly'
        23: from /var/www/discourse/lib/discourse_redis.rb:59:in `block (3 levels) in <class:DiscourseRedis>'
        22: from /var/www/discourse/lib/discourse_redis.rb:59:in `public_send'
        21: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:425:in `expire'
        20: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:69:in `synchronize'
        19: from /usr/local/lib/ruby/2.7.0/monitor.rb:202:in `mon_synchronize'
        18: from /usr/local/lib/ruby/2.7.0/monitor.rb:202:in `synchronize'
        17: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:69:in `block in synchronize'
        16: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:426:in `block in expire'
        15: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rack-mini-profiler-2.3.1/lib/mini_profiler/profiling_methods.rb:85:in `block in profile_method'
        14: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:131:in `call'
        13: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:237:in `process'
        12: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:325:in `logging'
        11: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:238:in `block in process'
        10: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:389:in `ensure_connected'
         9: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:248:in `block (2 levels) in process'
         8: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:131:in `block in call'
         7: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:279:in `read'
         6: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:268:in `io'
         5: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:280:in `block in read'
         4: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:378:in `read'
         3: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:45:in `gets'
         2: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:52:in `_read_from_socket'
         1: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:52:in `loop'
/var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:56:in `block in _read_from_socket': Redis::TimeoutError (Redis::TimeoutError)
        33: from /var/www/discourse/lib/sidekiq/pausable.rb:83:in `block (2 levels) in extend_lease_thread'
        32: from /var/www/discourse/lib/sidekiq/pausable.rb:83:in `synchronize'
        31: from /var/www/discourse/lib/sidekiq/pausable.rb:84:in `block (3 levels) in extend_lease_thread'
        30: from /usr/local/lib/ruby/2.7.0/set.rb:328:in `each'
        29: from /usr/local/lib/ruby/2.7.0/set.rb:328:in `each_key'
        28: from /var/www/discourse/lib/sidekiq/pausable.rb:85:in `block (4 levels) in extend_lease_thread'
        27: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rails_multisite-2.5.0/lib/rails_multisite/connection_management.rb:76:in `with_connection'
        26: from /var/www/discourse/lib/sidekiq/pausable.rb:86:in `block (5 levels) in extend_lease_thread'
        25: from /var/www/discourse/lib/discourse_redis.rb:59:in `block (2 levels) in <class:DiscourseRedis>'
        24: from /var/www/discourse/lib/discourse_redis.rb:29:in `ignore_readonly'
        23: from /var/www/discourse/lib/discourse_redis.rb:59:in `block (3 levels) in <class:DiscourseRedis>'
        22: from /var/www/discourse/lib/discourse_redis.rb:59:in `public_send'
        21: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:425:in `expire'
        20: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:69:in `synchronize'
        19: from /usr/local/lib/ruby/2.7.0/monitor.rb:202:in `mon_synchronize'
        18: from /usr/local/lib/ruby/2.7.0/monitor.rb:202:in `synchronize'
        17: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:69:in `block in synchronize'
        16: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis.rb:426:in `block in expire'
        15: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rack-mini-profiler-2.3.1/lib/mini_profiler/profiling_methods.rb:85:in `block in profile_method'
        14: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:131:in `call'
        13: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:237:in `process'
        12: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:325:in `logging'
        11: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:238:in `block in process'
        10: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:389:in `ensure_connected'
         9: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:248:in `block (2 levels) in process'
         8: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:131:in `block in call'
         7: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:279:in `read'
         6: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:268:in `io'
         5: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/client.rb:280:in `block in read'
         4: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:378:in `read'
         3: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:45:in `gets'
         2: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:52:in `_read_from_socket'
         1: from /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:52:in `loop'
/var/www/discourse/vendor/bundle/ruby/2.7.0/gems/redis-4.2.5/lib/redis/connection/ruby.rb:56:in `block in _read_from_socket': Connection timed out (Redis::TimeoutError)
^[[A  ^[[A^[[B       server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
connection to server was lost
EXCEPTION: psql failed: connection to server was lost

Consistently, the process will reach this far into the restore process, then hang on that last (85th) ALTER TABLE. I extracted my backup’s dump.sql, and the 85th is, if I’m counting right, this “public.reviewables” one:

Any idea from the above what might be going wrong?

我想我已经找到问题所在了。我本应该在新的主机上运行一次 ./discourse-setup,以便:(1) 创建交换文件,以及 (2) 设置合理的 db_shared_buffers 值。这两个配置中有一个错误,或者两个都有问题,导致了持续的挂起。

好眼力!欢迎回来,也欢迎你加入“自己回答自己的问题”俱乐部!:wink: 我有一大堆这类主题,不过我相信很多已经被删除了。

另一件事是复制 app.yml,但你还是得记得交换操作。除了这个交换的小麻烦外,如果 S3 配置已包含在 yml 文件中,那么这个 yml 文件就足够了。

很高兴你已恢复正常运行!