Problem rendering images in notification channels

Hello,

None of my notification channels are able to send the graph image, this is the error log:

t=2018-01-10T17:20:01+0100 lvl=info msg=“New state change” logger=alerting.resultHandler alertId=1 newState=alerting prev state=pending
t=2018-01-10T17:20:01+0100 lvl=info msg=Rendering logger=png-renderer path="dashboard-solo/db/sdm-hlr_fe?&panelId=9"
t=2018-01-10T17:20:01+0100 lvl=eror msg=“failed to render an image” logger=png-renderer error="exit status 1"
t=2018-01-10T17:20:01+0100 lvl=dbug msg=“Image rendered” logger=png-renderer path=/aplicaciones/grafana/data/png/kCDzMKAz7uNXJzzIVu6r.png

Do you have any idea of what could be the problem?

Thanks.

could be timing out, how long does the query take to execute?

I’m not sure, how can I know it? In the logs you can see that the error is in the same second when the alert is fired.

Finally, it’s not a timeout problem. I run a tcpdump and graphite replies quickly:

So it seems a grafana internal problem rendering the image, but I don’t know how to troubleshoot it.