Timeouts during batch statement execution

[Earl Lapus]

Hi All,

I am frequently getting the following exception when executing batch statements:

File "cassandra/cluster.py", line 1710, in cassandra.cluster.Session.execute08:26:58

File "cassandra/cluster.py", line 3343, in cassandra.cluster.ResponseFuture.result08:26:58

cassandra.protocol.ServerError: <Error from server: code=0000 [Server error] message="com.google.common.util.concurrent.UncheckedExecutionException: com.google.common.util.concurrent.UncheckedExecutionException: java.lang.RuntimeException: org.apache.cassandra.exceptions.ReadTimeoutException: Operation timed out - received only 4 responses.">

I've set the consistency level of my BatchSatement object to LOCAL_QUORUM.

Can anyone point me to a any config or settings in my connection that I should check or tweak to somehow resolve this issue?

Thanks,

Earl

[Alan Boudreault]

Hello,

How much data are you trying to fetch with that batch statement? The error happens on the server. You might be interested to look at your `read_request_timeout_in_ms` cassandra setting (and other *timeout* options). 

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Alan Boudreault

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[Earl Lapus]

Hi,

On Thursday, October 26, 2017 at 9:48:00 AM UTC-7, Alan Boudreault wrote:

Hello,

How much data are you trying to fetch with that batch statement? The error happens on the server. You might be interested to look at your `read_request_timeout_in_ms` cassandra setting (and other *timeout* options). 

The batch statement are actually inserts, it is not fetching anything.

I'll try checking the read_request_timeout_in_ms value in the server.

Thanks Alan...

-Earl-

[Earl Lapus]

Hi,

How much data are you trying to fetch with that batch statement? The error happens on the server. You might be interested to look at your `read_request_timeout_in_ms` cassandra setting (and other *timeout* options). 

The batch statement are actually inserts, it is not fetching anything.

I'll try checking the read_request_timeout_in_ms value in the server.

So, apparently I do not have access to the server... I do not know the exact value that is assigned to read_request_timeout_in_ms.

However, I tried playing around with the cassandra.policies.RetryPolicy class and tried setting that to retry_policy of the BatchStatement object to RETRY.

What happened was that the program runs longer (~4 times longer, so it is able to insert more data) before it eventually times out.

Is this a right path to somehow mitigate the issue without having to change anything on the server? What about the RETRY_NEXT_HOST... is it a viable option for the retry policy given the issues I am experiencing?

Thanks,

Earl

[Alan Boudreault]

Well, if your frequently get that timeout error, it might be better to change the way your app works and/or split into multiple smaller batches. Otherwise, yeah the retry policy could be a way to mitigate the issue for the moment.

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