[users at bb.net] And even more multi-master anecdotes.
Neil Gilmore
ngilmore at grammatech.com
Thu Aug 17 15:10:01 UTC 2017
Hi everyone.
This is a sort of extension to my original message.
I had to restart one of our other masters this morning. It apparently
lost its WAMP connection, whihc happens on occasion. The symptoms are
that none of its builders show up in the UI. The master itself was
running, though it may depend on the definition of 'running'. The
process was present, but it sat for minutes after its last log message,
which is very unusual for that master (it's the one that does most of
the builds).
I've also found that the stop command is nearly useless for our masters.
If they've been up for a while, doing things, they don't ever seem to
actually shut down. In this morning's case, I did the stop command. The
log showed the process getting the SIGTERM. Then I waited for 10
minutes. The process didn't stop. I finally killed it (and a regular
kill won't do it, I have to -9) because I have people asking me about it
constantly when it's not working right.
I'll also point out that we've been accumulating integrity errors in the
database again. They look like this in the UI master's log:
sqlalchemy.exc.IntegrityError: (IntegrityError) update or
delete on table "changes" violates foreign key constraint
"changes_parent_changeids_fkey" on table "changes"
DETAIL: Key (changeid)=(4188) is still referenced from table
"changes".
'DELETE FROM changes WHERE changes.changeid IN
(%(changeid_1)s, %(changeid_2)s, %(changeid_3)s, %(changeid_4)s,
%(changeid_5)s, %(changeid_6)s, %(changeid_7)s, %(changeid_8)s,
%(changeid_9)s, %(changeid_10)s, %(changeid_11)s, %(changeid_12)s,
%(changeid_13)s, %(changeid_14)s, %(changeid_15)s, %(changeid_16)s,
%(changeid_17)s, %(changeid_18)s, %(changeid_19)s, %(changeid_20)s,
%(changeid_21)s, %(changeid_22)s, %(changeid_23)s, %(changeid_24)s,
%(changeid_25)s, %(changeid_26)s, %(changeid_27)s, %(changeid_28)s,
%(changeid_29)s, %(changeid_30)s, %(changeid_31)s, %(changeid_32)s,
%(changeid_33)s, %(changeid_34)s, %(changeid_35)s, %(changeid_36)s,
%(changeid_37)s, %(changeid_38)s, %(changeid_39)s, %(changeid_40)s,
%(changeid_41)s, %(changeid_42)s, %(changeid_43)s, %(changeid_44)s,
%(changeid_45)s, %(changeid_46)s, %(changeid_47)s, %(changeid_48)s,
%(changeid_49)s, %(changeid_50)s, %(changeid_51)s, %(changeid_52)s,
%(changeid_53)s, %(changeid_54)s, %(changeid_55)s, %(changeid_56)s,
%(changeid_57)s, %(changeid_58)s, %(changeid_59)s, %(changeid_60)s,
%(changeid_61)s, %(changeid_62)s, %(changeid_63)s, %(changeid_64)s,
%(changeid_65)s, %(changeid_66)s, %(changeid_67)s, %(changeid_68)s,
%(changeid_69)s, %(changeid_70)s, %(changeid_71)s, %(changeid_72)s,
%(changeid_73)s, %(changeid_74)s, %(changeid_75)s, %(changeid_76)s,
%(changeid_77)s, %(changeid_78)s, %(changeid_79)s, %(changeid_80)s,
%(changeid_81)s, %(changeid_82)s, %(changeid_83)s, %(changeid_84)s,
%(changeid_85)s, %(changeid_86)s, %(changeid_87)s, %(changeid_88)s,
%(changeid_89)s, %(changeid_90)s, %(changeid_91)s, %(changeid_92)s,
%(changeid_93)s, %(changeid_94)s, %(changeid_95)s, %(changeid_96)s,
%(changeid_97)s, %(changeid_98)s, %(changeid_99)s, %(changeid_100)s)'
{'changeid_100': 4180, 'changeid_29': 4251, 'changeid_28': 4252,
'changeid_27': 4253, 'changeid_26': 4254, 'changeid_25': 4255,
'changeid_24': 4256, 'changeid_23': 4257, 'changeid_22': 4258,
'changeid_21': 4259, 'changeid_20': 4260, 'changeid_89': 4191,
'changeid_88': 4192, 'changeid_81': 4199, 'changeid_80': 4200,
'changeid_83': 4197, 'changeid_82': 4198, 'changeid_85': 4195,
'changeid_84': 4196, 'changeid_87': 4193, 'changeid_86': 4194,
'changeid_38': 4242, 'changeid_39': 4241, 'changeid_34': 4246,
'changeid_35': 4245, 'changeid_36': 4244, 'changeid_37': 4243,
'changeid_30': 4250, 'changeid_31': 4249, 'changeid_32': 4248,
'changeid_33': 4247, 'changeid_98': 4182, 'changeid_99': 4181,
'changeid_96': 4184, 'changeid_97': 4183, 'changeid_94': 4186,
'changeid_95': 4185, 'changeid_92': 4188, 'changeid_93': 4187,
'changeid_90': 4190, 'changeid_91': 4189, 'changeid_63': 4217,
'changeid_62': 4218, 'changeid_61': 4219, 'changeid_60': 4220,
'changeid_67': 4213, 'changeid_66': 4214, 'changeid_65': 4215,
'changeid_64': 4216, 'changeid_69': 4211, 'changeid_68': 4212,
'changeid_16': 4264, 'changeid_17': 4263, 'changeid_14': 4266,
'changeid_15': 4265, 'changeid_12': 4268, 'changeid_13': 4267,
'changeid_10': 4270, 'changeid_11': 4269, 'changeid_18': 4262,
'changeid_19': 4261, 'changeid_70': 4210, 'changeid_71': 4209,
'changeid_72': 4208, 'changeid_73': 4207, 'changeid_74': 4206,
'changeid_75': 4205, 'changeid_76': 4204, 'changeid_77': 4203,
'changeid_78': 4202, 'changeid_79': 4201, 'changeid_45': 4235,
'changeid_44': 4236, 'changeid_47': 4233, 'changeid_46': 4234,
'changeid_41': 4239, 'changeid_40': 4240, 'changeid_43': 4237,
'changeid_42': 4238, 'changeid_49': 4231, 'changeid_48': 4232,
'changeid_4': 4276, 'changeid_5': 4275, 'changeid_6': 4274,
'changeid_7': 4273, 'changeid_1': 4279, 'changeid_2': 4278,
'changeid_3': 4277, 'changeid_8': 4272, 'changeid_9': 4271,
'changeid_58': 4222, 'changeid_59': 4221, 'changeid_52': 4228,
'changeid_53': 4227, 'changeid_50': 4230, 'changeid_51': 4229,
'changeid_56': 4224, 'changeid_57': 4223, 'changeid_54': 4226,
'changeid_55': 4225}
We did have the UI master get stopped again for being OOM, somewhere
north of 50G. It's currently 46.8, and been running only a couple days.
My plan, when I get time, is to use some stuff we have in our own
product based on guppy to see what's going on in memory, but attaching
gdb to it and using PyRun_SimpleString() to run the heap checking stuff.
But for the time being, I can keep restarting things.
My gut feeling is that I'm going to have to shut everything down and
start with a clean database.
Neil Gilmore
raito at raito.com
On 8/10/2017 3:39 PM, Pierre Tardy wrote:
> Mmh.. sounds like you found a memory leak in the UI.
>
> Several points to check that could be out of control for UI:
> Message could be queuing up over hanged (or badly closed) websockets
> REST queries data could keep some reference in some way, which would
> make them just accumulate in memory.
> sombody is doing huge REST apis queries. It is unfortunatly quite easy
> to just hit /api/v2/builds, and dump the whole build db.
> This wouldn't go all the way to 45GB IMO.
>
> During my perf tests, I saw the logs system are quite memory hungry,
> and its buildbot is trading memory for cpu if the master can't keepup
> recording all the logs in the data (nothing fancy. the twisted queues
> will just be growing waiting for callbacks to be called).
> Due to several encoding and decoding, the memory usage in the log
> queue could be 2-4 times the amount of actual log bytes processed.
> anyway, this is probably not your problem.
>
> You can look at https://github.com/tardyp/buildbot_profiler maybe
> improve it to add a memory profiler..
>
>
> Pierre
>
> Le jeu. 10 août 2017 à 21:52, Neil Gilmore <ngilmore at grammatech.com
> <mailto:ngilmore at grammatech.com>> a écrit :
>
> Hi all,
>
> A couple of times in the last couple weeks, the master running our UI
> has crashed/exited/ceased to run. This most recent time it was a
> MemoryError, backed up by the kernel log saying it was OOM.
> Current run
> shows it using 43.1G memory. Seems like a lot, doesn't it? The other 2
> larger masters (the ones actually running builds) are about 2G,
> and the
> remaining, smallest one is about 1.7G.
>
> What does the UI hold onto that makes it so large?
>
> I'm supposed to get some heap profiling thingy wedged into
> buildbot so I
> can try to figure it out. My current plan is to introduce a new build
> step (like our current custom ones) that triggers the profiling
> process,
> create a sort of dummy build using the step, and create a force
> scheduler to trigger that build. That'll keep it on our UI master
> anyway. Is there a better way to trigger such code in the master at
> arbitrary times?
>
> I'm also starting to get complaints (and I've noticed this
> myself), that
> sometimes queued builds take a long time to start after the previous
> build finishes. Sometimes on the order of a half-hour or more. Or at
> least it appears so. I'm going on what the UI tells me. I haven't
> tried
> delving into the logs of the master controlling the builds to match up
> times. Any ideas? I'm afraid I'm not up on exactly how/when builds are
> supposed to get started.
>
> And out database seems to be accumulating integrity errors again.
>
> Neil Gilmore
> raito at raito.com <mailto:raito at raito.com>
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