Hi Anthony,
Not sure normally, but at the moment when we were investigating the
issue there were 21 .crf files in disk-store (on one server) with
default max-oplog-size (1GB) and compaction-threshold (50%).
BRs/Jakov
On 02. 12. 2021. 17:06, Anthony Baker wrote:
Related but different question: how many active oplogs do you normally see at
one time? You may want to adjust the max-oplog-size if the default of 1 GB is
too small.
On Dec 2, 2021, at 1:11 AM, Jakov Varenina
<jakov.varen...@est.tech<mailto:jakov.varen...@est.tech>> wrote:
Hi Dan,
We forget to mention that we actually configure off-heap for the regions, so
cache entry values are stored outside the heap memory. Only Oplog objects that
are not compacted and that have .crf file are referencing the live entries from
the cache. These Oplog objects are not stored in onlyDrfOplogs hashmap. In
onlyDrfOplogs map are only Oplog objects that are representing orphaned .drf
files (the one without accompanying .crf and .krf file). These objects have
been compacted and doesn't contain a reference to any live entry from the
cache. All of these 18G is actually occupied by empty pendingKrfTags hashmaps.
In this case there are 7680 Oplog objects stored in onlyDrfOplogs. Every Oplog
object has it's own regionMap hashmap. Every regionMap can contain hundreds of
empty pendingKrfTags hashMaps. When you bring all that together you get more
then 18G of unnecessary heap memory.
Thank you all for quick review of PR and fast response to our questions!
BRs/Jakov
On 02. 12. 2021. 00:25, Dan Smith wrote:
Interesting. It does look like that pendingKrfTags structure is wasting memory.
I think that retained heap of 20 gigabytes might include your entire cache,
because those objects have references back to the Cache object. However with 6K
oplogs each having an empty map with 4K elements that does add up.
-Dan
------------------------------------------------------------------------
*From:* Jakov Varenina <jakov.varen...@est.tech<mailto:jakov.varen...@est.tech>>
*Sent:* Tuesday, November 30, 2021 5:53 AM
*To:* dev@geode.apache.org<mailto:dev@geode.apache.org>
<dev@geode.apache.org<mailto:dev@geode.apache.org>>
*Subject:* Re: Question related to orphaned .drf files in disk-store
Hi Dan and all,
Just to provide you the additional picture that better represents the severity
of the problem with pendingKrfsTag. So when after you check the second picture
in below mail, then please come back and check this one also. Here you can see
that the pendingKerfTags is empty and has capacity of 9,192 allocated in memory.
Sorry for any inconvenience.
BRs/Jakov
On 30. 11. 2021. 09:32, Jakov Varenina wrote:
Hi Dan,
Thank you for your answer!
We have identify memory leak in Oplog objects that are representing orphaned
.drf files in heap memory. In below screenshoot you can see that 7680
onlyDrfOplogs consume more than 18 GB of heap which doesn't seem correct.
In below picture you can see that the drfOnlyPlog.Oplog.regionMap.pendingKrfTgs
structure is responsible for more then 95% of drfOnlyOplogs heap memory.
The pendingKrfTags structure is actually empty (although it consumes memory
because it was used previously and the size of the HashMap was not reduced) and
not used by the onlyDrfOplogs objects. Additionally, the regionMap.liveEntries
linked list has just one element (fake disk entry OlogDiskEntry indicating that
it is empty) and it is also not used. You can find more details why
pedingKrfTags sturcture remianed in memory for Oplog object representing
orphaned .drf file and possible solution in the following ticket and the PR:
https://issues.apache.org/jira/browse/GEODE-9854
<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fissues.apache.org%2Fjira%2Fbrowse%2FGEODE-9854&data=04%7C01%7Cbakera%40vmware.com%7Cbd2758bd10a54592fcef08d9b573cebe%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637740331264764503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=hEhzZk%2FZbFH%2B8812D7iRIU9ywNdV5CyW752HyvU3Tgo%3D&reserved=0>
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fapache%2Fgeode%2Fpull%2F7145&data=04%7C01%7Cbakera%40vmware.com%7Cbd2758bd10a54592fcef08d9b573cebe%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637740331264764503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Ua49Y%2F4PwKhQHHgz898uxDLde%2BZpZZFxMBY%2FgIL8%2BEE%3D&reserved=0
<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fapache%2Fgeode%2Fpull%2F7145&data=04%7C01%7Cbakera%40vmware.com%7Cbd2758bd10a54592fcef08d9b573cebe%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637740331264764503%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Ua49Y%2F4PwKhQHHgz898uxDLde%2BZpZZFxMBY%2FgIL8%2BEE%3D&reserved=0>
BRs/Jakov
On 24. 11. 2021. 23:12, Dan Smith wrote:
The .drf file contains destroy records for entries in any older oplog. So even
if the corresponding .crf file has been deleted, the .drf file with the same
number still needs to be retained until the older .crf files are all deleted.
7680 does seem like a lot of oplogs. That data structure is just references to
the files themselves, I don't think we are keeping the contents of the .drf
files in memory, except during recovery time.
-Dan
------------------------------------------------------------------------
*From:* Jakov Varenina <jakov.varen...@est.tech<mailto:jakov.varen...@est.tech>>
<mailto:jakov.varen...@est.tech>
*Sent:* Wednesday, November 24, 2021 11:13 AM
*To:* dev@geode.apache.org<mailto:dev@geode.apache.org> <mailto:dev@geode.apache.org>
<dev@geode.apache.org<mailto:dev@geode.apache.org>> <mailto:dev@geode.apache.org>
*Subject:* Question related to orphaned .drf files in disk-store
Hi devs,
We have noticed that disk-store folder can contain orphaned .drf files (only .drf file
without accompanying .crf and .krf file with the same id). Also, we have noticed that
these "orphaned" .drf are stored in heap (drfOnlyOplogs hash map with size 7680
in below picture):
Could you please tell us why do geode after compaction sometimes only keep .drf
and deletes the .crf and .krf files? Why do geode need those orphaned .drf
files?
BRs/Jakov
