[Redis] Add slow log metrics #1400
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Superseed #1330 Creates a histogram per redis command (HGET, LPUSH, etc) that is in the slow query log.
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| command_tag = 'command:{0}'.format(slowlog['command'].split()[0]) | ||
| value = slowlog['duration'] | ||
| self.histogram('redis.slowlog.micros', value, tags=tags + [command_tag]) |
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do you think it makes sense to convert to something other than microseconds (like milliseconds or seconds) since we don't really use that for any other metrics? If not, we might want to spell out "microseconds" or something. Maybe just me but I didn't know what "micros" meant without looking at the docs for the redis slowlog.
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on second thought, a conversion might be a bad idea because it would make the axis all wonky
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I think micros is good enough - or even in_micros which us better, IMHO, than μs which would likely become us anyway. We have used micros for a long time with cassandra metrics too.
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Cool metrics, interested to see what sort of data we can get from this on prod. Do you know if the commands in transactions will show up or will it just show up as |
| if max_slow_entries > DEFAULT_MAX_SLOW_ENTRIES: | ||
| self.warning("Redis {0} is higher than {1}. Defaulting to {1}."\ | ||
| "If you need a higher value, please set {0} in your check config"\ | ||
| .format(max_slow_entries, DEFAULT_MAX_SLOW_ENTRIES)) |
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This will result in having a string like
Redis 256 is higher than 128. Defaulting to 128. If you need a higher value please set 256 in your check config
Which is not super understandable?
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Agreed - the wording here should help the user understand what it is we're trying to tell them.
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Arf i reused the same variable name, max_slow_entries was supposed to be "slowlog-max-len" good catch!
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Yep @conorbranagan I think only individual commands go in the slow log, even if they're grouped in a transaction. |
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| # Max number of entries to fetch from the sloq query log | ||
| # By default, the check wil read this value from the redis config | ||
| # But if it's too high, it will default to 128 |
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"too high" should be spelled out, why is too high too high? "Higher than 128, due to potential increased latency to retrieve more than 128 slowlog entries every 15 seconds"...
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Thanks for the comments, i took care of them 6f52aee |
Supersedes #1330
Creates a histogram per redis command (HGET, LPUSH, etc) that is in the
slow query log.