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Displaying posts with tag: mysql communication errors (reset)
What exactly does log_warnings=2 log?

Have you ever wondered exactly does log_warnings=2 log? Well, I have, and finally decided to check the code. (The manual used to mention setting this to 2 for diagnosing some connection-related problems, but I didn’t run into that comment in my most recent search.)

Basically, in recent 5.6 source code, we find “log_warnings > 1″ in 7 files. In 5.5 source, it is only in 5 files. Here are the 7 files in 5.6: (line 460) (lines 4873, 10020, 11209) (line 912) (lines 1538, 1596, 1735, 2066) (lines 3585, 4684, 5405, 5436) (lines 9591, 9613, 11351) (line 791)

Long story short, the main (most common) ones are when a filesort fails ( or a failed login occurs ( Then there are some replication-specific instances where it logs extra info, such as master/slave/binlog info, “ignored” errors, and some summary stats …

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