[jboss-jira] [JBoss JIRA] Updated: (JGRP-1352) STATE: queue requests during state transfer
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https://issues.jboss.org/browse/JGRP-1352?page=com.atlassian.jira.plugin....
]
Bela Ban updated JGRP-1352:
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Description:
STATE should queue requests to be delivered to the application while a state transfer is
in progress.
Draft design:
* On STATE-REQ:
** If busy --> add request to queue, return
** Else --> processRequest
** Close MessageQueue and deliver all messages in it to the application
** Kick off a STABLE round, wait until it completes
** If MessageQueue is not empty --> processRequests()
* processRequest():
** Close BARRIER, suspend STABLE
** Get digest
** Open MessageQueue: all new messages will be queued now, rather than delivered to the
application
*** (Only MSG, not VIEW !)
** Open BARRIER (leave STABLE suspended !)
** Transfer state to state requester
** Resume STABLE
Advantages:
- The state provider is not blocked, e.g. to handle JOIN requests
- Only the state *requester* is blocked, this is OK though
- Between the state requests, the state provider gets a little breathing room to
process
queued-up messages, and to purge messages (through stability)
Misc:
- Should the MessageQueue use the disk to handle large message sets ?
- If modifications are idempotent, we *don't* need to queue messages (make this
configurable !)
(for example Infinispan ?)
was:
STATE should queue requests to be delivered to the application while a state transfer is
in progress.
Draft design:
- On STATE-REQ:
- If busy --> add request to queue, return
- Else --> processRequest
- Close MessageQueue and deliver all messages in it to the application
- Kick off a STABLE round, wait until it completes
- If MessageQueue is not empty --> processRequests()
- processRequest():
- Close BARRIER, suspend STABLE
- Get digest
- Open MessageQueue: all new messages will be queued now, rather than delivered to the
application
- (Only MSG, not VIEW !)
- Open BARRIER (leave STABLE suspended !)
- Transfer state to state requester
- Resume STABLE
Advantages:
- The state provider is not blocked, e.g. to handle JOIN requests
- Only the state *requester* is blocked, this is OK though
- Between the state requests, the state provider gets a little breathing room to
process
queued-up messages, and to purge messages (through stability)
Misc:
- Should the MessageQueue use the disk to handle large message sets ?
- If modifications are idempotent, we *don't* need to queue messages (make this
configurable !)
(for example Infinispan ?)
STATE: queue requests during state transfer
-------------------------------------------
Key: JGRP-1352
URL: https://issues.jboss.org/browse/JGRP-1352
Project: JGroups
Issue Type: Feature Request
Reporter: Bela Ban
Assignee: Bela Ban
Fix For: 3.1
STATE should queue requests to be delivered to the application while a state transfer is
in progress.
Draft design:
* On STATE-REQ:
** If busy --> add request to queue, return
** Else --> processRequest
** Close MessageQueue and deliver all messages in it to the application
** Kick off a STABLE round, wait until it completes
** If MessageQueue is not empty --> processRequests()
* processRequest():
** Close BARRIER, suspend STABLE
** Get digest
** Open MessageQueue: all new messages will be queued now, rather than delivered to the
application
*** (Only MSG, not VIEW !)
** Open BARRIER (leave STABLE suspended !)
** Transfer state to state requester
** Resume STABLE
Advantages:
- The state provider is not blocked, e.g. to handle JOIN requests
- Only the state *requester* is blocked, this is OK though
- Between the state requests, the state provider gets a little breathing room to
process
queued-up messages, and to purge messages (through stability)
Misc:
- Should the MessageQueue use the disk to handle large message sets ?
- If modifications are idempotent, we *don't* need to queue messages (make this
configurable !)
(for example Infinispan ?)
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