Hi Dimitris,
Thanks for fast response.
1. I double checked, load_catalog_in_background is false , so even if I
restart catalog separately, it should not ask for full updates, right ?
2. Start loading those big tables, thanks, we will try this.
3. The catalog actually already takes 3-4 times memory than what in
impala 2.3 , and I doubt if we set Java Heap Size of Catalog Server in Bytes a
bigger value, it will eat more memory.
Thanks.
Songbo
发件人: Dimitris Tsirogiannis [mailto:dtsirogian...@cloudera.com]
发送时间: 2016年9月23日 13:03
收件人: user@impala.incubator.apache.org
主题: Re: 答复: 答复: Catalog Server Out of memory when upgrading from CDH 5.5 -> 5.7
You may want to consider the following steps:
1. Restart the entire cluster and not just the catalog. If an impalad detects a
change in the catalog (caused by a restart) it asks for full updates.
2. Verify that the load_catalog_in_background is set to false. If that is the
case and there is no workload, the catalog shouldn't be active and the memory
utilization should stay flat.
3. Start loading those big tables, ideally one at a time by issuing a REFRESH
statement. See if the metadata of some tables are too big causing the 2GB limit
to be exceeded. If so, you may want to consider dropping incremental stats (if
used) or merging small files (if any).
4. Monitor memory consumption. There might be some increase in memory
consumption in 5.7 but not in the order of 3-4X.
5. Resume normal workloads.
Dimitris
On Thu, Sep 22, 2016 at 9:45 PM, 廖松博
<liaoson...@gridsum.com<mailto:liaoson...@gridsum.com>> wrote:
Hi Dimitris,
statestore_frequency_update_ms not change during the update, is 2000ms
by default. And not more frequent REFRESH statement.
Actually we have 2 problem here:
1. the size of the serialized metadata of some tables exceed the maximum
allowed size of a byte array (2GB). The potential reason are :
a) Before the upgrading, the number of partitions and metadata of per
table are added day by day , but once we upgrade and restart the catalog, the
entire metadata of per table is transferred to catalog, so this transferring
exceed the maximum allowed size of a byte array, does it make sense?
2. The memory usage of catalog server increase continuously , and before
the upgrade, catalog server only use 20G memory but now it reach our limit
whether the limit is 32G or 96G. So I doubt there is a memory leak or
inefficient GC
And I see the issue https://issues.cloudera.org/browse/IMPALA-3910, seems that
it is related to my problem, but why the memory usage of catalog server
increase continuously after upgrading.
Thanks
Songbo
发件人: Dimitris Tsirogiannis
[mailto:dtsirogian...@cloudera.com<mailto:dtsirogian...@cloudera.com>]
发送时间: 2016年9月23日 11:33
收件人: user@impala.incubator.apache.org<mailto:user@impala.incubator.apache.org>
抄送: Matthew Jacobs
主题: Re: 答复: Catalog Server Out of memory when upgrading from CDH 5.5 -> 5.7
That error message indicates that the size of the serialized metadata of some
tables exceed the maximum allowed size of a byte array (2GB) and doesn't have
anything to do with the size of the heap. The logs indicate a large number of
refresh tables that could trigger this kind of errors, especially if these
tables have large metadata and/or incremental stats. You may want to see if
there are any changes in the workload (e.g. more frequent REFRESH statements
than before) and if the value of the statestore_frequency_update_ms was changed
after the upgrade.
On Thu, Sep 22, 2016 at 7:24 PM, 廖松博
<liaoson...@gridsum.com<mailto:liaoson...@gridsum.com>> wrote:
Hi,
The event is the upgrading from CDH 5.5 -> 5.7. And the Operation is
the regular operations with Impala 2.3 which we work well with for a long time
, but after the upgrading, it consume so much memory.
It seems a memory leak, because as follow chart:
[cid:image001.jpg@01D21582.157D2320]
when we use impala 2.3, it use 20G memory more or less, but when we upgrade to
2.5 and set Java Heap Size of Catalog Server in Bytes = 32 G, but the catalog
server consume the 32G rapidly, and we reset Java Heap Size of Catalog Server
in Bytes to 64G , it also increase to 64G in a not long time.
So I double if it is a memory leak and I see the issue
https://issues.cloudera.org/browse/IMPALA-3568 , is it the root cause ?
And the attached is the catalog server log and it contains the :
java.lang.OutOfMemoryError: Requested array size exceeds VM limit.
1. Is the root cause of the memory leak?
2. Any way to find the table which cause the exception?
Thanks.
Songbo
发件人: Dimitris Tsirogiannis
[mailto:dtsirogian...@cloudera.com<mailto:dtsirogian...@cloudera.com>]
发送时间: 2016年9月23日 8:49
收件人: user@impala.incubator.apache.org<mailto:user@impala.incubator.apache.org>
抄送: Matthew Jacobs
主题: Re: Catalog Server Out of memory