sendWakeup: invalid argument (Bad file descriptor)

[jsommr]

Had to restart PostgREST because of this error:

postgrest: c_poll: permission denied (Operation not permitted)
postgrest: sendWakeup: invalid argument (Bad file descriptor)
172.19.0.1 - - [18/Apr/2016:11:11:23 +0000] "GET / HTTP/1.1" 200 - "" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0"
Control.AutoUpdate.mkAutoUpdate: worker thread exited with exception: sendWakeup: invalid argument (Bad file descriptor)
Control.AutoUpdate.mkAutoUpdate: worker thread exited with exception: sendWakeup: invalid argument (Bad file descriptor)
Control.AutoUpdate.mkAutoUpdate: worker thread exited with exception: sendWakeup: invalid argument (Bad file descriptor)

I'm using Docker (begriffs/postgrest)

[begriffs]

Looks like issue #557 turned out to be more of a problem then we thought. I'm going to close that other issue because this one has more details.

Approximately how long was postgrest running before this happened?

[jsommr]

Hard to say. I start and stop PostgREST all the time. Less than ½ hour and more than 5 minutes I guess. Haven't experienced this issue before though, but will keep you posted if I see it again.

[jsommr]

Perhaps timestamps in the log would make things easier?

[begriffs]

Possible causes

• A revival of this ghc bug
• Incompatibility of the binary I built in Ubuntu with the debian:jessie Docker image
• Docker file handling incompatible with Control.AutoUpdate

Debugging suggestion

Make a custom Docker image that builds off begriffs/postgrest and adds an strace:

strace -ff -e trace=file -p <postgrest-pid>

This will show us the files it is trying to access.

[jsommr]

While installing strace i noticed that ps aux returned

COMMAND
postgrest postgres://......
/bin/bash
[sleep] <defunct>
[sleep] <defunct>
ps aux

When I pinged PostgREST i got a response, and this was logged:

sendWakeup: invalid argument (Bad file descriptor)
172.19.0.1 - - [20/Apr/2016:08:17:23 +0000] "GET / HTTP/1.1" 200 - "" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:45.0) ....

The following requests got rejected with

Control.AutoUpdate.mkAutoUpdate: worker thread exited with exception: sendWakeup: invalid argument (Bad file descriptor)

After restarting, ps aux had no [sleep] and PostgREST worked as expected.

[jsommr]

Since PostgREST is always given pid 1 in the docker container I assume the strace command should be

strace -ff -e trace=file -p 1

The error I'm getting as root is:

strace: attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted

[ruslantalpa]

please try the 4.3 relaase in docker postgrest/postgrest and see if it works there.