I have implemented the above logic as part of OAK-1117 [1]. With this in place number of call made to Mongo on restarts of Adobe CQ goes down from 42000 to 25000 significantly reducing the startup time when Mongo is remote!!
regards Chetan [1] https://issues.apache.org/jira/browse/OAK-1117 Chetan Mehrotra On Thu, Oct 24, 2013 at 3:23 PM, Chetan Mehrotra <chetan.mehro...@gmail.com> wrote: > I am trying to prototype an approach. Would come up with a patch for > this soon. So far I was going with the reverse approach whereby when I > fetch a node I retrieve some extra child rows [1] in same call to > determine if it has any children. > > But given that number of read would far exceed number of writes it > would be better to perform extra update call. I would try to come up > with a patch for this > > regards > Chetan > [1] by adding an or clause to fetch node with id say "^2:/foo/.*" to > fetch child node for a parent with id "1:/foo". > Chetan Mehrotra > > > On Thu, Oct 24, 2013 at 3:08 PM, Thomas Mueller <muel...@adobe.com> wrote: >> Hi, >> >> Yes, you are right. It should be relatively easy to implement (low risk). >> >> Regards, >> Thomas >> >> >> On 10/24/13 10:12 AM, "Marcel Reutegger" <mreut...@adobe.com> wrote: >> >>>> The disadvantage is, when a node is added, either: >>>> >>>> - then the parent needs to be checked whether is already has this flag >>>>set >>>> (if it is in the cache), or >>> >>>I'd say a parent node is likely in the cache because oak will read it >>>first before >>>it is able to add a child. >>> >>>> - the parent needs to be updated to set the flag >>> >>>that's correct. though you only have to do it when it isn't set already. >>>and >>>the check should be cheap in most cases, because the node is in the cache. >>> >>>regards >>> marcel >>> >>
