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https://issues.apache.org/jira/browse/CASSANDRA-11748?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Michael Fong updated CASSANDRA-11748:
-------------------------------------
    Description: 
We have observed multiple times when a multi-node C* (v2.0.17) cluster ran into 
OOM in bootstrap during a rolling upgrade process from 1.2.19 to 2.0.17. 

Here is the simple guideline of our rolling upgrade process
1. Update schema on a node, and wait until all nodes to be in schema version 
agreemnt - via nodetool describeclulster
2. Restart a Cassandra node
3. After restart, there is a chance that the the restarted node has different 
schema version.
4. All nodes in cluster start to rapidly exchange schema information, and any 
of node could run into OOM. 

The following is the system.log that occur in one of our 2-node cluster test bed
----------------------------------
Before rebooting node 2:
Node 1: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,326 MigrationManager.java 
(line 328) Gossiping my schema version 4cb463f8-5376-3baf-8e88-a5cc6a94f58f

Node 2: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,122 MigrationManager.java 
(line 328) Gossiping my schema version 4cb463f8-5376-3baf-8e88-a5cc6a94f58f

After rebooting node 2, 
Node 2: DEBUG [main] 2016-04-19 11:18:18,016 MigrationManager.java (line 328) 
Gossiping my schema version f5270873-ba1f-39c7-ab2e-a86db868b09b

The node2  keeps submitting the migration task over 100+ times to the other 
node.
INFO [GossipStage:1] 2016-04-19 11:18:18,261 Gossiper.java (line 1011) Node 
/192.168.88.33 has restarted, now UP
INFO [GossipStage:1] 2016-04-19 11:18:18,262 TokenMetadata.java (line 414) 
Updating topology for /192.168.88.33
...
DEBUG [GossipStage:1] 2016-04-19 11:18:18,265 MigrationManager.java (line 102) 
Submitting migration task for /192.168.88.33
... ( over 100+ times)
----------------------------------
On the otherhand, Node 1 keeps updating its gossip information, followed by 
receiving and submitting migrationTask afterwards: 

INFO [RequestResponseStage:3] 2016-04-19 11:18:18,333 Gossiper.java (line 978) 
InetAddress /192.168.88.34 is now UP
...
DEBUG [MigrationStage:1] 2016-04-19 11:18:18,496 
MigrationRequestVerbHandler.java (line 41) Received migration request from 
/192.168.88.34.
…… ( over 100+ times)
DEBUG [OptionalTasks:1] 2016-04-19 11:19:18,337 MigrationManager.java (line 
127) submitting migration task for /192.168.88.34
.....  (over 50+ times)

On the side note, we have over 200+ column families defined in Cassandra 
database, which may related to this amount of rpc traffic.

P.S.2 The over requested schema migration task will eventually have 
InternalResponseStage performing schema merge operation. Since this operation 
requires a compaction for each merge and is much slower to consume. Thus, the 
back-pressure of incoming schema migration content objects consumes all of the 
heap space and ultimately ends up OOM!


  was:
We have observed multiple times when a multi-node C* (v2.0.17) cluster ran into 
OOM in bootstrap during a rolling upgrade process from 1.2.19 to 2.0.17. 

Here is the simple guideline of our rolling upgrade process
1. Update schema on a node, and wait until all nodes to be in schema version 
agreemnt - via nodetool describeclulster
2. Restart a Cassandra node
3. After restart, there is a chance that the the restarted node has different 
schema version.
4. All nodes in cluster start to rapidly exchange schema information, and any 
of node could run into OOM. 

The following is the system.log that occur in one of our 2-node cluster test bed
----------------------------------
Before rebooting node 2:
Node 1: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,326 MigrationManager.java 
(line 328) Gossiping my schema version 4cb463f8-5376-3baf-8e88-a5cc6a94f58f

Node 2: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,122 MigrationManager.java 
(line 328) Gossiping my schema version 4cb463f8-5376-3baf-8e88-a5cc6a94f58f

After rebooting node 2, 
Node 2: DEBUG [main] 2016-04-19 11:18:18,016 MigrationManager.java (line 328) 
Gossiping my schema version f5270873-ba1f-39c7-ab2e-a86db868b09b

The node2  keeps submitting the migration task over 100+ times to the other 
node.
INFO [GossipStage:1] 2016-04-19 11:18:18,261 Gossiper.java (line 1011) Node 
/192.168.88.33 has restarted, now UP
INFO [GossipStage:1] 2016-04-19 11:18:18,262 TokenMetadata.java (line 414) 
Updating topology for /192.168.88.33
...
DEBUG [GossipStage:1] 2016-04-19 11:18:18,265 MigrationManager.java (line 102) 
Submitting migration task for /192.168.88.33
... ( over 100+ times)
----------------------------------
On the otherhand, Node 1 keeps updating its gossip information, followed by 
receiving and submitting migrationTask afterwards: 

INFO [RequestResponseStage:3] 2016-04-19 11:18:18,333 Gossiper.java (line 978) 
InetAddress /192.168.88.34 is now UP
...
DEBUG [MigrationStage:1] 2016-04-19 11:18:18,496 
MigrationRequestVerbHandler.java (line 41) Received migration request from 
/192.168.88.34.
…… ( over 100+ times)
DEBUG [OptionalTasks:1] 2016-04-19 11:19:18,337 MigrationManager.java (line 
127) submitting migration task for /192.168.88.34
.....  (over 50+ times)

On the side note, we have over 200+ column families defined in Cassandra 
database, which may related to this amount of rpc traffic.



> Schema version mismatch may leads to Casandra OOM at bootstrap during a 
> rolling upgrade process
> -----------------------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-11748
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-11748
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: Rolling upgrade process from 1.2.19 to 2.0.17. 
> CentOS 6.6
> Occurred in different C* node of different scale of deployment (2G ~ 5G)
>            Reporter: Michael Fong
>            Priority: Critical
>
> We have observed multiple times when a multi-node C* (v2.0.17) cluster ran 
> into OOM in bootstrap during a rolling upgrade process from 1.2.19 to 2.0.17. 
> Here is the simple guideline of our rolling upgrade process
> 1. Update schema on a node, and wait until all nodes to be in schema version 
> agreemnt - via nodetool describeclulster
> 2. Restart a Cassandra node
> 3. After restart, there is a chance that the the restarted node has different 
> schema version.
> 4. All nodes in cluster start to rapidly exchange schema information, and any 
> of node could run into OOM. 
> The following is the system.log that occur in one of our 2-node cluster test 
> bed
> ----------------------------------
> Before rebooting node 2:
> Node 1: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,326 
> MigrationManager.java (line 328) Gossiping my schema version 
> 4cb463f8-5376-3baf-8e88-a5cc6a94f58f
> Node 2: DEBUG [MigrationStage:1] 2016-04-19 11:09:42,122 
> MigrationManager.java (line 328) Gossiping my schema version 
> 4cb463f8-5376-3baf-8e88-a5cc6a94f58f
> After rebooting node 2, 
> Node 2: DEBUG [main] 2016-04-19 11:18:18,016 MigrationManager.java (line 328) 
> Gossiping my schema version f5270873-ba1f-39c7-ab2e-a86db868b09b
> The node2  keeps submitting the migration task over 100+ times to the other 
> node.
> INFO [GossipStage:1] 2016-04-19 11:18:18,261 Gossiper.java (line 1011) Node 
> /192.168.88.33 has restarted, now UP
> INFO [GossipStage:1] 2016-04-19 11:18:18,262 TokenMetadata.java (line 414) 
> Updating topology for /192.168.88.33
> ...
> DEBUG [GossipStage:1] 2016-04-19 11:18:18,265 MigrationManager.java (line 
> 102) Submitting migration task for /192.168.88.33
> ... ( over 100+ times)
> ----------------------------------
> On the otherhand, Node 1 keeps updating its gossip information, followed by 
> receiving and submitting migrationTask afterwards: 
> INFO [RequestResponseStage:3] 2016-04-19 11:18:18,333 Gossiper.java (line 
> 978) InetAddress /192.168.88.34 is now UP
> ...
> DEBUG [MigrationStage:1] 2016-04-19 11:18:18,496 
> MigrationRequestVerbHandler.java (line 41) Received migration request from 
> /192.168.88.34.
> …… ( over 100+ times)
> DEBUG [OptionalTasks:1] 2016-04-19 11:19:18,337 MigrationManager.java (line 
> 127) submitting migration task for /192.168.88.34
> .....  (over 50+ times)
> On the side note, we have over 200+ column families defined in Cassandra 
> database, which may related to this amount of rpc traffic.
> P.S.2 The over requested schema migration task will eventually have 
> InternalResponseStage performing schema merge operation. Since this operation 
> requires a compaction for each merge and is much slower to consume. Thus, the 
> back-pressure of incoming schema migration content objects consumes all of 
> the heap space and ultimately ends up OOM!



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