RepoMirrors/postgres_exporter
1
0
Fork 0
mirror of https://github.com/prometheus-community/postgres_exporter synced 2025-04-26 13:08:01 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add retries to getServer() (#316)

Browse Source 
Some backstory
==============

I was attempting to use postgres_exporter with the official Docker
container (https://hub.docker.com/_/postgres) In a Kubernetes
StatefulSet, with a side-car configuration, but found that I wasn't able
to connect even with sharing the Postgres Unix listening socket, between
both containers. After copying the container over to an Alpine base I
quickly found out that the postgres_exporter was actually starting
before the main Postres container had dropped the unix socket onto the
file system, a quick work around is to write a bash for loop checking
for the existence of a unix socket, however this would require
maintaining a container, besides other users may find retries useful on
startup.

Implementation
==============

All changes are made to the getServer function and variables are
local, I was unsure if it was worth adding command line switches but
this would allow for a more sophisticated backOff loop in the future.

Hope this help, and let me know if you would like me to changes
anything.
This commit is contained in:
Dan Molik 2019-10-29 23:54:18 -04:00 committed by Will Rouesnel
parent 238f5c099a
commit 043e68e067
1 changed files with 21 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
cmd/postgres_exporter/postgres_exporter.go
View File

@ -863,17 +863,29 @@ func (s *Servers) GetServer(dsn string) (*Server, error) {
s.m.Lock() s.m.Lock()
defer s.m.Unlock() defer s.m.Unlock()
var err error var err error
server, ok := s.servers[dsn] var ok bool
if !ok { errCount := 0 // start at zero because we increment before doing work
server, err = NewServer(dsn, s.opts...) retries := 3
if err != nil { var server *Server
for {
if errCount++; errCount > retries {
return nil, err return nil, err
} }
s.servers[dsn] = server server, ok = s.servers[dsn]
} if !ok {
if err = server.Ping(); err != nil { server, err = NewServer(dsn, s.opts...)
delete(s.servers, dsn) if err != nil {
return nil, err time.Sleep(time.Duration(errCount) * time.Second)
continue
}
s.servers[dsn] = server
}
if err = server.Ping(); err != nil {
delete(s.servers, dsn)
time.Sleep(time.Duration(errCount) * time.Second)
continue
}
break
} }
return server, nil return server, nil
} }