[infinispan-issues] [JBoss JIRA] (ISPN-3766) WriteSkewException

[V L (JIRA)]

     [ https://issues.jboss.org/browse/ISPN-3766?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

V L updated ISPN-3766:
----------------------

    Description: 
I'm not new with Infinispan, we use it from 5.3 version. Now I'm working on integrating WriteSkew functional in our project, but unfortunately it's not worked properly in our situation.

We use infinispan like a "cache" for some data source (doesn't matter for what)

The problem is that WriteSkewException is available in specific situation, here are steps for reproducing:
1) begin tx -> create an new element -> commit tx. 
2) wait until cache expires. cache is empty now
3) being tx -> try to get element from cache, but it isn't found, so loading element from data source and put it to the cache via putForExternalRead for read access outside of current transaction.
4) make some modification with element -> put element to cache -> commit tx
Commit operation throws WriteSkewException 

Here is log:
TX BEGIN status=6 thread=1
PUT id=key1, tx=0, thread=1 cache size=1, cache contains={ key1:value }
TX COMMIT. status='0', thread='1'

TX BEGIN. status='6', thread='1'
SIZE id='1', tx='0', thread='1' size='1', contains='{ key: null }'
PUT_FER id='1', tx='0', thread='1' size='1', contains='{ key:null }'
PUT id='1', tx='0', thread='1' size='1', contains='{ key:value }'
TX COMMIT. status='0', thread='1'
ISPN000005: Detected write skew on key [1]. Another process has changed the entry since we last read it! Unable to copy entry for update.
Exception executing call org.infinispan.transaction.WriteSkewException: Detected write skew.

I think I found the problem is in "get" method. When I invoke the get method with key that not available in cache, infinispan create an "null" element in cache. This element doesn't update by putForExternalRead method (look at log above). If you skip get method invocation everithing is working fine. Everithing is working ok if you skip step 2 of scenarion too.

  was:
I'm not new with Infinispan, we use it from 5.3 version. Now I'm working on integrating WriteSkew functional in our project, but unfortunately it's not worked properly in our situation.

We use infinispan like a "cache" for some data source (doesn't matter for what)

The problem is that WriteSkewException is available in specific situation, here are steps for reproducing:
1) begin tx -> create an new element -> commit tx. 
2) wait until cache expires. cache is empty now
3) being tx -> try to get element from cache, but it isn't found, so loading element from data source and put it to the cache via putForExternalRead for read access outside of current transaction.
4) make some modification with element -> put element to cache -> commit tx
Commit operation throws WriteSkewException 

Here is log:
TX BEGIN. status='6', thread='1'
PUT id='1', tx='0', thread='1' size='1', contains='{ key:value }'
TX COMMIT. status='0', thread='1'

TX BEGIN. status='6', thread='1'
SIZE id='1', tx='0', thread='1' size='1', contains='{ key: null }'
PUT_FER id='1', tx='0', thread='1' size='1', contains='{ key:null }'
PUT id='1', tx='0', thread='1' size='1', contains='{ key:value }'
TX COMMIT. status='0', thread='1'
ISPN000005: Detected write skew on key [1]. Another process has changed the entry since we last read it! Unable to copy entry for update.
Exception executing call org.infinispan.transaction.WriteSkewException: Detected write skew.

I think I found the problem is in "get" method. When I invoke the get method with key that not available in cache, infinispan create an "null" element in cache. This element doesn't update by putForExternalRead method (look at log above). If you skip get method invocation everithing is working fine. Everithing is working ok if you skip step 2 of scenarion too.


    
> WriteSkewException 
> -------------------
>
>                 Key: ISPN-3766
>                 URL: https://issues.jboss.org/browse/ISPN-3766
>             Project: Infinispan
>          Issue Type: Bug
>          Components: Transactions
>    Affects Versions: 5.3.0.Final, 6.0.0.CR1, 6.0.0.Final
>            Reporter: V L
>            Assignee: Mircea Markus
>         Attachments: InfinispanTest.java
>
>
> I'm not new with Infinispan, we use it from 5.3 version. Now I'm working on integrating WriteSkew functional in our project, but unfortunately it's not worked properly in our situation.
> We use infinispan like a "cache" for some data source (doesn't matter for what)
> The problem is that WriteSkewException is available in specific situation, here are steps for reproducing:
> 1) begin tx -> create an new element -> commit tx. 
> 2) wait until cache expires. cache is empty now
> 3) being tx -> try to get element from cache, but it isn't found, so loading element from data source and put it to the cache via putForExternalRead for read access outside of current transaction.
> 4) make some modification with element -> put element to cache -> commit tx
> Commit operation throws WriteSkewException 
> Here is log:
> TX BEGIN status=6 thread=1
> PUT id=key1, tx=0, thread=1 cache size=1, cache contains={ key1:value }
> TX COMMIT. status='0', thread='1'
> TX BEGIN. status='6', thread='1'
> SIZE id='1', tx='0', thread='1' size='1', contains='{ key: null }'
> PUT_FER id='1', tx='0', thread='1' size='1', contains='{ key:null }'
> PUT id='1', tx='0', thread='1' size='1', contains='{ key:value }'
> TX COMMIT. status='0', thread='1'
> ISPN000005: Detected write skew on key [1]. Another process has changed the entry since we last read it! Unable to copy entry for update.
> Exception executing call org.infinispan.transaction.WriteSkewException: Detected write skew.
> I think I found the problem is in "get" method. When I invoke the get method with key that not available in cache, infinispan create an "null" element in cache. This element doesn't update by putForExternalRead method (look at log above). If you skip get method invocation everithing is working fine. Everithing is working ok if you skip step 2 of scenarion too.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira