Re: [Bigdata-developers] writeNodeRecursive warnings while DROPping large graph

[Bryan T. <br...@sy...>]

That is IO Wait (or sometimes GC) associated with flushing high level nodes
in the B+Tree to the disk.  Given the data I see above, it looks like IO
Wait was probably spiking.  Are you running against local SSD?  If you are
on EC2, have you exceeded your write rate throughput for the instances?

There are faster ways to drop an entire triple store or quad store.   But
dropping a large named graph out of a set of named graphs in a quad store
will incur a lot of IO.

Bryan

----
Bryan Thompson
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SYSTAP, LLC
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On Mon, Aug 31, 2015 at 1:56 PM, Jeremy J Carroll <jj...@sy...> wrote:

> We have had big problems dropping a large graph, I have just been looking
> at the logs and we seem to have many entries like
>
> WARN : 199265281      com.bigdata.journal.Journal.executorService942
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 2 records (#nodes=1, #leaves=1) in 8048ms :
> addrRoot=-1052669065178378143
> WARN : 199301423      com.bigdata.journal.Journal.executorService942
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 2 records (#nodes=1, #leaves=1) in 36141ms :
> addrRoot=-1052669099538116489
> WARN : 199817295      com.bigdata.journal.Journal.executorService1068
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 1 records (#nodes=1, #leaves=0) in 21813ms :
> addrRoot=-1052358706546595628
> WARN : 200111575      com.bigdata.journal.Journal.executorService18
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 2 records (#nodes=1, #leaves=1) in 5953ms :
> addrRoot=-1052338112178413386
> WARN : 200197937      com.bigdata.journal.Journal.executorService1070
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 1 records (#nodes=1, #leaves=0) in 10652ms :
> addrRoot=-1053867623046964134
> WARN : 200763920      com.bigdata.journal.Journal.executorService942
> com.bigdata.btree.AbstractBTree.writeNodeRecursive(AbstractBTree.java:3716):
> wrote: name=.spo.OCSP, 2 records (#nodes=1, #leaves=1) in 6214ms :
> addrRoot=-1052630260148849987
>
> can someone offer an interpretation?
>
> thanks
>
> Jeremy
>
>
>
>
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