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https://issues.apache.org/jira/browse/HIVE-26404?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17578582#comment-17578582
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Stamatis Zampetakis edited comment on HIVE-26404 at 8/11/22 5:35 PM:
---------------------------------------------------------------------
There is question about where exactly do these Configuration objects come from
since it seems that the Cleaner is only using/passing one instance. It seems
that multiple configurations come up when SASL is enabled for HDFS and in
particular everything starts from this method:
https://github.com/apache/hadoop/blob/6463f86f83fc84ac1fb7e4ea1c4c0a4807ab82be/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/DataTransferSaslUtil.java#L190
The aforementioned line creates a copy of the configuration so basically there
will be as many configuration instances as {{SaslPropertiesResolver}} and there
is at least one created for each FileSystem object.
was (Author: zabetak):
There is question about where exactly do these Configuration objects come from
since it seems that the Cleaner is only using/passing one instance. It seems
that multiple configurations come up when SASL is enabled for HDFS and in
particular everything starts from this method:
https://github.com/apache/hadoop/blob/6463f86f83fc84ac1fb7e4ea1c4c0a4807ab82be/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/DataTransferSaslUtil.java#L190
> HMS memory leak when compaction cleaner fails to remove obsolete files
> ----------------------------------------------------------------------
>
> Key: HIVE-26404
> URL: https://issues.apache.org/jira/browse/HIVE-26404
> Project: Hive
> Issue Type: Bug
> Components: Metastore
> Affects Versions: 4.0.0-alpha-1
> Reporter: Stamatis Zampetakis
> Assignee: Stamatis Zampetakis
> Priority: Major
> Labels: pull-request-available
> Time Spent: 10m
> Remaining Estimate: 0h
>
> While investigating an issue where HMS becomes unresponsive we noticed a lot
> of failed attempts from the compaction Cleaner thread to remove obsolete
> directories with exceptions similar to the one below.
> {noformat}
> 2022-06-16 05:48:24,819 ERROR
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner: [Cleaner-executor-thread-0]:
> Caught exception when cleaning, unable to complete cleaning of
> id:4410976,dbname:my_database,tableName:my_table,partName:day=20220502,state:,type:MAJOR,enqueueTime:0,start:0,properties:null,runAs:some_user,tooManyAborts:false,hasOldAbort:false,highestWriteId:187502,errorMessage:null
> java.io.IOException: Not enough history available for (187502,x). Oldest
> available base:
> hdfs://nameservice1/warehouse/tablespace/managed/hive/my_database.db/my_table/day=20220502/base_0188687_v4297872
> at
> org.apache.hadoop.hive.ql.io.AcidUtils.getAcidState(AcidUtils.java:1432)
> at
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner.removeFiles(Cleaner.java:261)
> at
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner.access$000(Cleaner.java:71)
> at
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner$1.run(Cleaner.java:203)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:422)
> at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1898)
> at
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner.clean(Cleaner.java:200)
> at
> org.apache.hadoop.hive.ql.txn.compactor.Cleaner.lambda$run$0(Cleaner.java:105)
> at
> org.apache.hadoop.hive.ql.txn.compactor.CompactorUtil$ThrowingRunnable.lambda$unchecked$0(CompactorUtil.java:54)
> at
> java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1640)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
> at java.lang.Thread.run(Thread.java:748)
> {noformat}
> In addition the logs contained a large number of long JVM pauses as shown
> below and the HMS (RSZ) memory kept increasing at rate of 90MB per hour.
> {noformat}
> 2022-06-16 16:17:17,805 WARN
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 34346ms
> 2022-06-16 16:17:21,497 INFO
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 1690ms
> 2022-06-16 16:17:57,696 WARN
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 34697ms
> 2022-06-16 16:18:01,326 INFO
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 1628ms
> 2022-06-16 16:18:37,280 WARN
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 34453ms
> 2022-06-16 16:18:40,927 INFO
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 1646ms
> 2022-06-16 16:19:16,929 WARN
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 33997ms
> 2022-06-16 16:19:20,572 INFO
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 1637ms
> 2022-06-16 16:20:01,643 WARN
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 39329ms
> 2022-06-16 16:20:05,572 INFO
> org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor:
> [org.apache.hadoop.hive.metastore.metrics.JvmPauseMonitor$Monitor@5b022296]:
> Detected pause in JVM or host machine (eg GC): pause of approximately 1927ms
> {noformat}
> We took a heapdump of the HMS around the time that it becomes unresponsive
> and we have seen many Configuration objects (~40K) occupying more than 90% of
> the current heap (~9GB).
> {noformat}
> Class Name | Objects | Shallow Heap |
> Retained Heap
> ----------------------------------------------------------------------------------------------
> org.apache.hadoop.conf.Configuration | 39,452 | 1,893,696 |
> >= 8,560,573,960
> java.util.concurrent.ConcurrentHashMap | 155,863 | 9,975,232 |
> >= 4,696,003,968
> java.util.concurrent.ConcurrentHashMap$Node[]| 139,348 | 1,312,967,944 |
> >= 4,686,230,296
> java.util.Properties | 87,119 | 4,181,712 |
> >= 4,193,638,904
> java.util.Hashtable$Entry[] | 87,840 | 987,968,472 |
> >= 4,189,518,928
> java.util.concurrent.ConcurrentHashMap$Node | 99,097,078 | 3,171,106,496 |
> >= 3,375,319,552
> java.util.Hashtable$Entry | 100,047,081 | 3,201,506,592 |
> >= 3,201,551,936
> org.postgresql.jdbc.PgConnection | 6,488 | 830,464 |
> >= 551,442,952
> ----------------------------------------------------------------------------------------------
> {noformat}
> It turns out that these Configuration objects are all referenced by CACHE
> entries in org.apache.hadoop.fs.FileSystem$Cache.
> {noformat}
> Class Name
> | Shallow Heap | Retained Heap
> ----------------------------------------------------------------------------------------------------------------------
> org.apache.hadoop.fs.FileSystem$Cache @ 0x45403fe70
> | 32 | 108,671,824
> |- <class> class org.apache.hadoop.fs.FileSystem$Cache @ 0x45410c3e0
> | 8 | 544
> '- map java.util.HashMap @ 0x453ffb598
> | 48 | 92,777,232
> |- <class> class java.util.HashMap @ 0x4520382c8 System Class
> | 40 | 168
> |- entrySet java.util.HashMap$EntrySet @ 0x454077848
> | 16 | 16
> '- table java.util.HashMap$Node[32768] @ 0x463585b68
> | 131,088 | 92,777,168
> |- class java.util.HashMap$Node[] @ 0x4520b7790
> | 0 | 0
> '- [1786] java.util.HashMap$Node @ 0x451998ce0
> | 32 | 9,968
> |- <class> class java.util.HashMap$Node @ 0x4520b7728 System Class
> | 8 | 32
> '- value org.apache.hadoop.hdfs.DistributedFileSystem @ 0x452990178
> | 56 | 4,976
> |- <class> class org.apache.hadoop.hdfs.DistributedFileSystem @
> 0x45402e290| 8 | 4,664
> |- uri java.net.URI @ 0x451a05cd0 hdfs://nameservice1
> | 80 | 432
> |- dfs org.apache.hadoop.hdfs.DFSClient @ 0x451f5d9b8
> | 128 | 3,824
> '- conf org.apache.hadoop.hive.conf.HiveConf @ 0x453a34b38
> | 80 | 250,160
> ----------------------------------------------------------------------------------------------------------------------
> {noformat}
> As long as they are in the CACHE they cannot be garbage collected so this
> leads to a memory leak.
> The memory leak seems to come from the fact the compaction Cleaner attempts
> to
> [remove|https://github.com/apache/hive/blob/69e6a5a4151100849d2b03b6b14b1605c3abc3f1/ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/Cleaner.java#L266]
> the obsolete files and fails. The exception does not allow the [filesystem
> cleanup|https://github.com/apache/hive/blob/69e6a5a4151100849d2b03b6b14b1605c3abc3f1/ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/Cleaner.java#L270]
> to take place so we are leaving filesystem entries in the CACHE and
> subsequently configuration objects.
> Although, the HMS unresponsiveness in this use-case may not be due to lack of
> memory the leak needs to be addressed to avoid hitting OOM.
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