[ 
https://issues.apache.org/jira/browse/IGNITE-5714?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16817923#comment-16817923
 ] 

Aleksey Plekhanov commented on IGNITE-5714:
-------------------------------------------

[~agoncharuk], as already described by [~Alexey Kuznetsov] we can't remove 
thread ID from MVCC candidate because it's needed for explicit locks 
(IgniteCache#lock, IgniteCache#lockAll) when an explicit transaction is not 
started. In this case, the lock is held by a thread, not by a transaction.

But I think we can get rid of thread id usage in MVCC candidate for all cases 
when the lock is held by a transaction. And more carefully split the logic of 
lock checking for locks held by threads and by transactions (for example remove 
methods like {{lockedLocallyByIdOrThread).}} In this case, there is no thread 
id update needed when thread for the transaction is switched.

What do you think about such solution?

> Implementation of suspend/resume for pessimistic transactions
> -------------------------------------------------------------
>
>                 Key: IGNITE-5714
>                 URL: https://issues.apache.org/jira/browse/IGNITE-5714
>             Project: Ignite
>          Issue Type: Sub-task
>          Components: general
>            Reporter: Alexey Kuznetsov
>            Assignee: Aleksey Plekhanov
>            Priority: Major
>              Labels: iep-34
>
> Support transaction suspend()\resume() operations for pessimistic 
> transactions. Resume can be called in another thread.
>    _+But there is a problem+_: Imagine, we started pessimistic transaction in 
> thread T1 and then perform put operation, which leads to sending 
> GridDistributedLockRequest to another node. Lock request contains thread id 
> of the transaction. Then we call suspend, resume in another thread and we 
> also must send messages to other nodes to change thread id. 
> It seems complicated task.It’s better to get rid of sending thread id to the 
> nodes.
> We can use transaction xid on other nodes instead of thread id. Xid is sent 
> to nodes in GridDistributedLockRequest#nearXidVer
>    _+Proposed solution+_ : On remote nodes instead of thread id of near 
> transaction GridDistributedLockRequest#threadId use its xid 
> GridDistributedLockRequest#nearXidVer.
> Remove usages of near transaction's thread id on remote nodes.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to