Hi Vishal, This might be an indication that you are sending several requests in parallel without waiting for a response and you need to introduce throttling in your application, as Dinesh mentioned.
This issue is related to the usage of the DataStax C++ driver, you should consider starting a new mail thread on the driver mailing list: https://groups.google.com/a/lists.datastax.com/forum/#!forum/cpp-driver-user Regards, Jorge El mar., 20 nov. 2018 a las 13:42, <vishal1.sha...@ril.com> escribió: > 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.jo...@yahoo.com.INVALID [mailto: > dinesh.jo...@yahoo.com.INVALID] > Sent: Tuesday, November 20, 2018 3:15 PM > To: dev@cassandra.apache.org > 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.sha...@ril.com > <vishal1.sha...@ril.com> 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. > "Confidentiality Warning: This message and any attachments are intended > only for the use of the intended recipient(s). > are confidential and may be privileged. If you are not the intended > recipient. you are hereby notified that any > review. re-transmission. conversion to hard copy. copying. circulation or > other use of this message and any attachments is > strictly prohibited. If you are not the intended recipient. please notify > the sender immediately by return email. > and delete this message and any attachments from your system. > > Virus Warning: Although the company has taken reasonable precautions to > ensure no viruses are present in this email. > The company cannot accept responsibility for any loss or damage arising > from the use of this email or attachment." >
