Ruby on Rails查询到MySQL并不总是返回新添加的信息

Question

I've taken over a Red Hat Enterprise Linux 5 system running Ruby (v1.8.5) on Rails (v2.3.5) with Passenger (v2.2.9), Thinking Sphinx (v1.3.14) and MySQL (v5.0.77-log). I know they're all out of date, but that's not the problem.

The users of that system have noticed that data input recently doesn't show up on a query like older data does. For instance, here's a snippet from the log when older data is looked up:

  7 Query SELECT * FROM `patients` WHERE (`patients`.`id` = 618) 7 Query SELECT count(*) AS count_all FROM `notes` WHERE (patient_id = 618) 7 Query SELECT * FROM `notes` WHERE (`notes`.`id` IN (2238,2237,2092,2088)) 7 Query SHOW FIELDS FROM `categories` 7 Query SELECT * FROM `categories` WHERE (`categories`.`id` = 3) 7 Query SELECT * FROM `users` WHERE (`users`.`id` = 2) 7 Query SELECT * FROM `categories` WHERE (`categories`.`id` = 2) 7 Query SELECT * FROM `categories` WHERE (`categories`.`id` = 1) 7 Query SELECT * FROM `users` WHERE (`users`.`id` = 6) 7 Query BEGIN 7 Query UPDATE `sessions` SET `data` = '[removed]\\n', `updated_at` = '2013-04-12 20:08:26' WHERE `id` = 1836 7 Query COMMIT 

So MySQL is returning four notes (with ids of 2238, 2237, 2092, and 2088) for patient 618.

On the other hand, if I pick a patient added to the system last Tuesday that I know has three notes associated with him, I get this:

  8 Query SELECT * FROM `patients` WHERE (`patients`.`id` = 1157) 8 Query SELECT count(*) AS count_all FROM `notes` WHERE (patient_id = 1157) 8 Query BEGIN 8 Query UPDATE `sessions` SET `data` = '[removed]=\\n', `updated_at` = '2013-04-12 20:19:00' WHERE `id` = 1836 8 Query COMMIT 

The whole "SELECT * FROM notes " section is missing. I know that the notes are there because I can see them if I search for them by hand.

A few extra potentially-salient points:

• This system hadn't been rebooted in over three years, and things like httpd and sqld weren't set up to autostart on reboot, so I'm not sure if there is something else that needs to be restarted.
• I have no background in Ruby on Rails. I have no idea what Thinking Sphinx is, but I do know that I was getting HTTP 500 errors before I ran the command "rake -f ~user/project/Rakefile ts:start RAILS_ENV=production".
• The system had just been migrated from one virtual machine farm to another (V-to-V, in other words), but I've examined all the ways in which this might have affected the RoR installation, and have come to the conclusion that it couldn't have affected any of the files or functionality.

Any help you could give me would be greatly appreciated!

Answer 1

It turned out to be a problem with Thinking Sphinx.

TS was set up to run its reindexing service (rake ts:reindex) hourly as the user who owns the project. When I was debugging the issue, I ran it as root, which changed the ownership of all the index files to root. When the user's reindexing job ran afterwards, it returned either a

Permission denied, will not index. Try --rotate option.

error, or a

Resource temporarily unavailable, will not index. Try --rotate option.

error.

I ended up recreating the index files from scratch as the non-root user, and now it works again.