I just don't understand completely all the design thoughts behind the lease time idea. I've read the conversations here, but still its not all clear.
https://issues.apache.org/jira/browse/OAK-3424 https://issues.apache.org/jira/browse/OAK-3449 https://issues.apache.org/jira/browse/OAK-2739 I'm hardly trying to understand whats going on from the source code. 😑😥 On Sun, Aug 6, 2017 at 11:38 AM, Mostafa Mahdieh <[email protected]> wrote: > Thanks for your suggestions. > > I'm wondering what happens in the worst case if I disable the lease check. > > In case multiple instances of jackrabbit are run using the same clusterId, > what are the consequences? Is this all related to logging issues or does it > have any worse consequences? > > On Wed, Aug 2, 2017 at 1:54 PM, Stefan Egli <[email protected]> wrote: > >> Hi Mostafa, >> >> I'd suggest to narrow down why that lease update failed, esp if you have >> it reproducible. By default a lease is updated every 10 seconds and is >> valid for 2min (and could in theory be changed but that's not recommended >> necessarily). >> >> Besides mentioned DB issues, other cases where lease updates failed were >> JVMs running low on memory thus doing too long GC-stop-the-worlds. >> >> If you can rule out both, then here's some more ideas to investigate: >> >> a) check for warnings in the form of: "BackgroundLeaseUpdate.execute: >> time >> since last renewClusterIdLease() call longer than expected" to see if the >> lease update became slow already before it finally expired. Perhaps that >> gives some clues already. >> >> b) enable trace logging for >> 'org.apache.jackrabbit.oak.plugins.document.ClusterNodeInfo' to see all >> details about lease updates happening (or not). >> >> c) analyse thread dumps to rule out blocked lease update thread >> >> Cheers, >> Stefan >> >> On 01/08/17 15:45, "Mostafa Mahdieh" <[email protected]> wrote: >> >> >Hi, >> > >> >I'm using jackrabbit oak as the content repository of a document >> >management >> >system product. Currently there is no need to scale out, therefore I'm >> >using jackrabbit oak in a single node environment. However, I'm >> >experiencing issues related to clustering and lease time, such as the >> >following exception which is appearing all over my tomcat logs: >> > >> >WARN: Background operation failed: >> >org.apache.jackrabbit.oak.plugins.document.DocumentStoreException: This >> >oak >> >instance failed to update the lease in time and can therefore no longer >> >access this DocumentNodeStore. >> > >> >After some research, It seems that there is no way to use jackrabbit oak >> >forcing it to use a single node and not having any concerns related to >> >clustering. >> > >> >Am I using the right tool? I thought maybe jackrabbit 2 might be better >> >for >> >my current use case, however oak seemed as the future of jackrabbit, and >> >attracted me (adding scalability is also in my future vision). Do you >> >suggest oak for my usecase or jackrabbit 2? How can I adapt oak for a >> >single node environment without getting issues regarding lease time and >> >clustering? >> > >> >Best Regards >> >-- >> >Mostafa Mahdieh >> >> >> > > > -- > Mostafa Mahdieh > -- Mostafa Mahdieh
