On 22.06.09 17:37, Jim Fulton wrote: > > On Jun 22, 2009, at 11:31 AM, Alan Runyan wrote: > >> On Mon, Jun 22, 2009 at 10:06 AM, Andreas Jung<li...@zopyx.com> wrote: >>> On 22.06.09 16:56, Pedro Ferreira wrote: >>>> Hello all, >>>> We occasionally get some messages like this in the logs: >>>> >>>> 2009-06-22T14:12:42 (30651/137.138.128.213:35787) Transaction blocked >>>> waiting for storage. Clients waiting: 1. >>>> >>>> But today we eventually got to: >>>> >>>> 2009-06-22T16:00:11 (30651/137.138.4.153:53416) Transaction blocked >>>> waiting for storage. Clients waiting: 204. >>>> >>>> Which lasted some minutes. During that time, our system seemed to >>>> hang, >>>> even if it was possible to connect to the db through the command line. >>>> It eventually went back to normal by itself. >>>> Any clue on what might have caused this? >>> The reason is likely a long running transaction. Since the storage >>> server >>> is single-threaded, a long running transaction will block pending >>> requests. >> >> Question: >> Will the ZEO server respond to LOAD requests from ZEO clients while >> WRITEs are pending? > > > Yes, however, if the last phase of 2-phase commit takes long enough, > clients will become blocked altogether. This is because vote requests > get blocked and eventually, all of the client threads are blocked voting. I think Dieter's patch is related to this issue:
https://bugs.launchpad.net/zodb/+bug/373625 Andreas
begin:vcard fn:Andreas Jung n:Jung;Andreas org:ZOPYX Ltd. & Co. KG adr;quoted-printable:;;Charlottenstr. 37/1;T=C3=BCbingen;;72070;Germany email;internet:i...@zopyx.com title:CEO tel;work:+49-7071-793376 tel;fax:+49-7071-7936840 tel;home:+49-7071-793257 x-mozilla-html:FALSE url:www.zopyx.com version:2.1 end:vcard
_______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
