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Posted to jira@kafka.apache.org by "Dong Lin (JIRA)" <ji...@apache.org> on 2017/09/13 00:28:00 UTC
[jira] [Updated] (KAFKA-5879) Controller should read the latest
IsrChangeNotification znodes when handling IsrChangeNotification event
[ https://issues.apache.org/jira/browse/KAFKA-5879?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Dong Lin updated KAFKA-5879:
----------------------------
Description:
Currently controller can be very inefficient in handling IsrChangeNotification event because it may need to access znode O(n^2) times to handle O( n ) IsrChangeNotification znodes.
For example, say there are 100 IsrChangeNotification nodes added to the zookeeper. This will generate 100 IsrChangeNotification events with children [1], [1, 2], [1, 2, 3], ... [1, 2, .. 100]. Let's say the controller now needs to handle the IsrChangeNotification event with children [1, 2, ... 100]. Controller will read zookeeper 100 times, delete these 100 znodes, which further generates 100 IsrChangeNotification events with children count from 0 to 99.
The main cause of the problem is that, controller will attempt to access zookeeper n times, where n is the count of the children at the time the IsrChangeNotification event is generated, even though there is no IsrChangeNotification znodes in the zookeeper.
was:
Currently controller can be very inefficient in handling IsrChangeNotification event because it may need to access znode O(n^2) times to handle O (n) IsrChangeNotification znodes.
For example, say there are 100 IsrChangeNotification nodes added to the zookeeper. This will generate 100 IsrChangeNotification events with children [1], [1, 2], [1, 2, 3], ... [1, 2, .. 100]. Let's say the controller now needs to handle the IsrChangeNotification event with children [1, 2, ... 100]. Controller will read zookeeper 100 times, delete these 100 znodes, which further generates 100 IsrChangeNotification events with children count from 0 to 99.
The main cause of the problem is that, controller will attempt to access zookeeper n times, where n is the count of the children at the time the IsrChangeNotification event is generated, even though there is no IsrChangeNotification znodes in the zookeeper.
> Controller should read the latest IsrChangeNotification znodes when handling IsrChangeNotification event
> --------------------------------------------------------------------------------------------------------
>
> Key: KAFKA-5879
> URL: https://issues.apache.org/jira/browse/KAFKA-5879
> Project: Kafka
> Issue Type: Bug
> Reporter: Dong Lin
> Assignee: Dong Lin
> Priority: Critical
>
> Currently controller can be very inefficient in handling IsrChangeNotification event because it may need to access znode O(n^2) times to handle O( n ) IsrChangeNotification znodes.
> For example, say there are 100 IsrChangeNotification nodes added to the zookeeper. This will generate 100 IsrChangeNotification events with children [1], [1, 2], [1, 2, 3], ... [1, 2, .. 100]. Let's say the controller now needs to handle the IsrChangeNotification event with children [1, 2, ... 100]. Controller will read zookeeper 100 times, delete these 100 znodes, which further generates 100 IsrChangeNotification events with children count from 0 to 99.
> The main cause of the problem is that, controller will attempt to access zookeeper n times, where n is the count of the children at the time the IsrChangeNotification event is generated, even though there is no IsrChangeNotification znodes in the zookeeper.
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