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Posted to issues@ignite.apache.org by "Vladimir Steshin (Jira)" <ji...@apache.org> on 2020/05/15 09:38:00 UTC
[jira] [Updated] (IGNITE-13014) Remove double checking of node
availability. Fix hardcoded values.
[ https://issues.apache.org/jira/browse/IGNITE-13014?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Vladimir Steshin updated IGNITE-13014:
--------------------------------------
Description:
For the present, we have duplicated checking of node availability. This prolongs node failure detection and gives no additional benefits. There are mesh and hardcoded values in this routine.
Let's imagine node 2 doesn't answer any more. Node 1 becomes unable to ping node 2 and asks Node 3 to establish permanent connection instead of node 2. Despite node 2 has been already pinged within configured timeouts, node 3 try to connect to node 2 too.
Disadvantages:
1) Possible long detection of node failure up to ServerImpl.CON_CHECK_INTERVAL + 2 * IgniteConfiguretion.failureDetectionTimeout + 300ms. See ‘WostCase.txt’
2) Unexpected, not-configurable decision to check availability of previous node based on ‘2 * ServerImpl.CON_CHECK_INTERVAL‘:
// We got message from previous in less than double connection check interval.
boolean ok = rcvdTime + CON_CHECK_INTERVAL * 2 >= now;
If ‘ok == true’ node 3 checks node 2.
3) Double node checking brings several not-configurable hardcoded delays:
Node 3 checks node 2 with hardcoded timeout 100ms:
ServerImpl.isConnectionRefused():
sock.connect(addr, 100);
Checking availability of previous node considers any exception but ConnectionException (connection refused) as existing connection. Even a timeout. See ServerImpl.isConnectionRefused().
was:
For the present, we have duplicated checking of node availability. This prolongs node failure detection and gives no additional benefits. There are mesh and hardcoded values in this routine.
Let's imagine node 2 doesn't answer any more. Node 1 becomes unable to ping node 2 and asks Node 3 to establish permanent connection instead of node 2. Despite node 2 has been already pinged within configured timeouts, node 3 try to connect to node 2 too.
Disadvantages:
1) Possible long detection of node failure up to ServerImpl.CON_CHECK_INTERVAL + 2 * IgniteConfiguretion.failureDetectionTimeout + 300ms. See ‘WostCase.txt’
2) Unexpected, not-configurable decision to check availability of previous node based on ‘2 * ServerImpl.CON_CHECK_INTERVAL‘:
// We got message from previous in less than double connection check interval.
boolean ok = rcvdTime + CON_CHECK_INTERVAL * 2 >= now;
If ‘ok == true’ node 3 checks node 2.
3) Double node checking brings several not-configurable hardcoded delays:
Node 3 checks node 2 with hardcoded timeout 100ms:
ServerImpl.isConnectionRefused():
sock.connect(addr, 100);
Checking availability of previous node considers any exception but ConnectionException (connection refused) as existing connection. Even a timeout. See ServerImpl.isConnectionRefused().
> Remove double checking of node availability. Fix hardcoded values.
> ------------------------------------------------------------------
>
> Key: IGNITE-13014
> URL: https://issues.apache.org/jira/browse/IGNITE-13014
> Project: Ignite
> Issue Type: Improvement
> Reporter: Vladimir Steshin
> Assignee: Vladimir Steshin
> Priority: Major
>
> For the present, we have duplicated checking of node availability. This prolongs node failure detection and gives no additional benefits. There are mesh and hardcoded values in this routine.
> Let's imagine node 2 doesn't answer any more. Node 1 becomes unable to ping node 2 and asks Node 3 to establish permanent connection instead of node 2. Despite node 2 has been already pinged within configured timeouts, node 3 try to connect to node 2 too.
> Disadvantages:
> 1) Possible long detection of node failure up to ServerImpl.CON_CHECK_INTERVAL + 2 * IgniteConfiguretion.failureDetectionTimeout + 300ms. See ‘WostCase.txt’
> 2) Unexpected, not-configurable decision to check availability of previous node based on ‘2 * ServerImpl.CON_CHECK_INTERVAL‘:
> // We got message from previous in less than double connection check interval.
> boolean ok = rcvdTime + CON_CHECK_INTERVAL * 2 >= now;
> If ‘ok == true’ node 3 checks node 2.
> 3) Double node checking brings several not-configurable hardcoded delays:
> Node 3 checks node 2 with hardcoded timeout 100ms:
> ServerImpl.isConnectionRefused():
> sock.connect(addr, 100);
> Checking availability of previous node considers any exception but ConnectionException (connection refused) as existing connection. Even a timeout. See ServerImpl.isConnectionRefused().
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