[OSM-dev] Rendering Chain Issue

[Frederik Ramm]

Hi,

On 06/19/2012 03:45 PM, Richard Ive wrote:
> In my second screen shot you can see the two tiles that get requested
> just before the freeze. I can consistently make this happen and resolve
> the hang by restarting Tirex, which would suggest the problem is there,
> however looking through all the logs I don't see anything related to
> this issue.

If a Tirex render process dies - something that you would see in the 
"daemon" syslog - then the effect is that tirex-master still lists the 
request as being rendered but there will be no "mapnik" process in the 
system that claims to be rendering this job. If this happens often 
enough, the Tirex queue will be full. Look at tirex-status and compare 
the list of tiles being rendered with the list of "mapnik" processes. If 
processes are indeed dying, activate verbose=true in the Tirex config 
and try to find out; it might well be a funny Mapnik exception (albeit 
unlikely that something breaks a whole column of tiles).

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"