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https://issues.apache.org/jira/browse/KAFKA-4841?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Dong Lin updated KAFKA-4841:
----------------------------
Description:
KAFKA-4820 allows new request to be enqueued to unsent by user thread while
some other thread does poll(...). This causes problem in the following scenario:
- Thread A calls poll(...) and is blocked on select(...)
- Thread B enqueues a request into unsent of ConsumerNetworkClient for node N
- Thread A calls checkDisconnects(now) -> client.connectionFailed(N)
Because no attempts have been made to connection to node N yet, there is no
state for node N and connectionFailed(N) would throw exception. Note that this
problem only occurs when one thread is able to enqueue requests while another
thread is in the process of `poll(...)`
The solution is to only consider a connection has failed if attempts have been
made to connect to this node AND the connection state is DISCONNECTED.
was:
KAFKA-4820 allows new request to be enqueued to unsent by user thread while
some other thread does poll(...). This causes problem in the following scenario:
Thread A calls poll(...) and is blocked on select(...)
Thread B enqueues a request into unsent of ConsumerNetworkClient for node N
Thread A calls checkDisconnects(now) -> client.connectionFailed(N)
Because no attempts have been made to connection to node N yet, there is no
state for node N and connectionFailed(N) would throw exception.
The solution is to only consider a connection has failed if attempts have been
made to connect to this node AND the connection state is DISCONNECTED.
> NetworkClient should only consider a connection to be fail after attempt to
> connect
> -----------------------------------------------------------------------------------
>
> Key: KAFKA-4841
> URL: https://issues.apache.org/jira/browse/KAFKA-4841
> Project: Kafka
> Issue Type: Bug
> Reporter: Dong Lin
> Assignee: Dong Lin
>
> KAFKA-4820 allows new request to be enqueued to unsent by user thread while
> some other thread does poll(...). This causes problem in the following
> scenario:
> - Thread A calls poll(...) and is blocked on select(...)
> - Thread B enqueues a request into unsent of ConsumerNetworkClient for node N
> - Thread A calls checkDisconnects(now) -> client.connectionFailed(N)
> Because no attempts have been made to connection to node N yet, there is no
> state for node N and connectionFailed(N) would throw exception. Note that
> this problem only occurs when one thread is able to enqueue requests while
> another thread is in the process of `poll(...)`
> The solution is to only consider a connection has failed if attempts have
> been made to connect to this node AND the connection state is DISCONNECTED.
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