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RE: [External]Re: I/O threads busy error


This issue is mainly being observed when the table whose data is being fetched contains a column which stores a very large text(12.5 KB). Could this be a possible reason? How can I solve the issue? Which settings do I have to change?

-----Original Message-----
From: dinesh.joshi@xxxxxxxxx.INVALID [mailto:dinesh.joshi@xxxxxxxxx.INVALID] 
Sent: Tuesday, November 20, 2018 3:15 PM
To: dev@xxxxxxxxxxxxxxxxxxxx
Subject: [External]Re: I/O threads busy error

You're probably hitting this - https://github.com/datastax/cpp-driver/blob/2.0/src/session.cpp#L740
From my reading it feels you may want to throttle your queries or play around with the driver settings. Essentially it seems the number of queries you're issuing is greater than what the cluster can handle and therefore they're queuing up in the driver.
Dinesh 

    On Monday, November 19, 2018, 10:24:10 PM PST, Vishal1.Sharma@xxxxxxx <Vishal1.Sharma@xxxxxxx> wrote:  
 
 Dear all,
I've got a 2 node Cassandra cluster(3.11.2). I'm using Datastax's c++ driver(ver 2.7) in my application to fetch/add data from the cluster(RHEL 6.9). Sometimes I'm getting the error "All connections on all I/O threads are busy" in my application.  I'm unable to figure out why I am getting this error infrequently and not everytime. 

Has anyone faced such errors before? Please let me know any possible reasons behind the issue.

Thanks and regards,
Vishal Sharma

P.S. I don't really know whether this is a Datastax driver's issue or Cassandra's issue that's why I'm posting this query here.
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