On Fri, Oct 1, 2010 at 4:00 AM, <renayama19661...@ybb.ne.jp> wrote: > Hi Andrew, > > Thank you for comment. > >> During crmd startup, one could read all the values from attrd into the >> hashtable. >> So the hashtable would only do something if only attrd went down. > > If attrd communicates with crmd at the time of start and reads the data of > the hash table, the problem > seems to be able to be settled. > > Is the change of this attrd and crmd difficult?
I dont think so. But its not a huge priority because I've never heard of attrd actually crashing. So while I agree that its theoretically a problem, in practice no-one is going to hit this in production. Even if they were unlucky enough to see it, at worst the resource is able to run on the node again - which doesn't seem that bad for a HA cluster :-) > > >> I mean: did you see this behavior in a production system, or only >> during testing when you manually killed attrd? > > We carry out kill-command by manual operation as one of the tests of the > trouble of the processes. > Our user minds behavior of the process trouble very much. > > Best Regards, > Hideo Yamauchi. > > --- Andrew Beekhof <and...@beekhof.net> wrote: > >> On Wed, Sep 29, 2010 at 3:59 AM, <renayama19661...@ybb.ne.jp> wrote: >> > Hi Andrew, >> > >> > Thank you for comment. >> > >> >> The problem here is that attrd is supposed to be the authoritative >> >> source for this sort of data. >> > >> > Yes. I understand. >> > >> >> Additionally, you don't always want attrd reading from the status >> >> section - like after the cluster restarts. >> > >> > The problem seems to be able to solve even that it retrieves a status >> > section from cib after >> attrd >> > rebooted. >> > "method2" which I suggested is such a meaning. >> >> > method 2)When attrd started, Attrd communicates with cib and receives >> >> > fail-count. >> > >> >> For failcount, the crmd could keep a hashtable of the current values >> >> which it could re-send to attrd if it detects a disconnection. >> >> But that might not be a generic-enough solution. >> > >> > If a Hash table of crmd can maintain it, it may be a good thought. >> > However, I have a feeling that the same problem happens when crmd causes >> > trouble and rebooted. >> >> During crmd startup, one could read all the values from attrd into the >> hashtable. >> So the hashtable would only do something if only attrd went down. >> >> > >> >> The chance that attrd dies _and_ there were relevant values for >> >> fail-count is pretty remote though... is this a real problem you've >> >> experienced or a theoretical one? >> > >> > I did not understand meanings well. >> > Does this mean that there is fail-count of attrd in the other node? >> >> I mean: did you see this behavior in a production system, or only >> during testing when you manually killed attrd? >> >> > >> > Best Regards, >> > Hideo Yamauchi. >> > >> > --- Andrew Beekhof <and...@beekhof.net> wrote: >> > >> >> On Mon, Sep 27, 2010 at 7:26 AM, �<renayama19661...@ybb.ne.jp> >> >> wrote: >> >> > Hi, >> >> > >> >> > When I investigated another problem, I discovered this phenomenon. >> >> > If attrd causes process trouble and does not restart, the problem does >> >> > not occur. >> >> > >> >> > Step1) After start, it causes a monitor error in UmIPaddr twice. >> >> > >> >> > Online: [ srv01 srv02 ] >> >> > >> >> > �Resource Group: UMgroup01 >> >> > � � UmVIPcheck (ocf::heartbeat:Dummy): Started srv01 >> >> > � � UmIPaddr � (ocf::heartbeat:Dummy2): � >> >> > � � >> > �Started srv01 >> >> > >> >> > Migration summary: >> >> > * Node srv02: >> >> > * Node srv01: >> >> > � UmIPaddr: migration-threshold=10 fail-count=2 >> >> > >> >> > Step2) Kill Attrd and Attrd reboots. >> >> > >> >> > Online: [ srv01 srv02 ] >> >> > >> >> > �Resource Group: UMgroup01 >> >> > � � UmVIPcheck (ocf::heartbeat:Dummy): Started srv01 >> >> > � � UmIPaddr � (ocf::heartbeat:Dummy2): � >> >> > � � >> > �Started srv01 >> >> > >> >> > Migration summary: >> >> > * Node srv02: >> >> > * Node srv01: >> >> > � UmIPaddr: migration-threshold=10 fail-count=2 >> >> > >> >> > Step3) It causes a monitor error in UmIPaddr. >> >> > >> >> > Online: [ srv01 srv02 ] >> >> > >> >> > �Resource Group: UMgroup01 >> >> > � � UmVIPcheck (ocf::heartbeat:Dummy): Started srv01 >> >> > � � UmIPaddr � (ocf::heartbeat:Dummy2): � >> >> > � � >> > �Started srv01 >> >> > >> >> > Migration summary: >> >> > * Node srv02: >> >> > * Node srv01: >> >> > � UmIPaddr: migration-threshold=10 fail-count=1 -----> >> >> > Fail-count return to the >> first. >> >> > >> >> > The problem is so that attrd disappears fail-count by >> >> > reboot.(Hash-tables is Lost.) >> >> > It is a problem very much that the trouble number of times is >> >> > initialized. >> >> > >> >> > I think that there is the following method. >> >> > >> >> > method 1)Attrd maintain fail-count as a file in "/var/run" directories >> >> > and refer. >> >> > >> >> > method 2)When attrd started, Attrd communicates with cib and receives >> >> > fail-count. >> >> > >> >> > Is there a better method? >> >> > >> >> > Please think about the solution of this problem. >> >> >> >> Hmmmm... a tricky one. >> >> >> >> The problem here is that attrd is supposed to be the authoritative >> >> source for this sort of data. >> >> Additionally, you don't always want attrd reading from the status >> >> section - like after the cluster restarts. >> >> >> >> For failcount, the crmd could keep a hashtable of the current values >> >> which it could re-send to attrd if it detects a disconnection. >> >> But that might not be a generic-enough solution. >> >> >> >> The chance that attrd dies _and_ there were relevant values for >> >> fail-count is pretty remote though... is this a real problem you've >> >> experienced or a theoretical one? >> >> >> >> _______________________________________________ >> >> Pacemaker mailing list: Pacemaker@oss.clusterlabs.org >> >> http://oss.clusterlabs.org/mailman/listinfo/pacemaker >> >> >> >> Project Home: http://www.clusterlabs.org >> >> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> >> Bugs: >> >> http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker >> >> >> > >> > >> > >> > _______________________________________________ >> > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org >> > http://oss.clusterlabs.org/mailman/listinfo/pacemaker >> > >> > Project Home: http://www.clusterlabs.org >> > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> > Bugs: >> > http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker >> > >> >> _______________________________________________ >> Pacemaker mailing list: Pacemaker@oss.clusterlabs.org >> http://oss.clusterlabs.org/mailman/listinfo/pacemaker >> >> Project Home: http://www.clusterlabs.org >> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> Bugs: >> http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker >> > > > _______________________________________________ > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: > http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker > _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker