Anuj, Thank you for your explanation. I had misread the documentation and was under the impression all these days that Hints_window refers to ‘time until deletion’. Also, thanks for the information about TCP settings, I will have to recheck the existing configuration. I will also test the performance improvement of increasing the threads for the hint delivery.
Thank you, Meg Mara From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in.INVALID] Sent: Tuesday, June 27, 2017 11:56 AM To: user@cassandra.apache.org Subject: Re: Hints files are not getting truncated Hi Meg, max_hint_window_in_ms =3 hrs means that if a node is down/unresponsive for more than 3 hrs, hints would not be stored for it any further until it becomes responsive again. It should not mean that already stored hints would be truncated after 3 hours. Regarding connection timeouts between DCs, please check your firewall settings and tcp settings on node. Firewall between the DC must not kill an idle connection which is still considered to be usable by Cassandra. Please see http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/troubleshooting/trblshootIdleFirewall.html . In multi dc setup, documentation recommends to increase number of threads. You can try increasing it and check whether it improves the situation. Thanks Anuj On Tue, Jun 27, 2017 at 9:47 PM, Meg Mara <mm...@digitalriver.com<mailto:mm...@digitalriver.com>> wrote: Hello, I am facing an issue with Hinted Handoff files in Cassandra v3.0.10. A DC1 node is storing large number of hints for DC2 nodes (we are facing connection timeout issues). The problem is that the hint files which are created on DC1 are not getting deleted after the 3 hour window. Hints are now being stored as flat files in the Cassandra home directory and I can see that old hints are being deleted but at a very slow pace. It still contains hints from May. max_hint_window_in_ms: 10800000 max_hints_delivery_threads: 2 Why do you suppose this is happening? Any suggestions or recommendations would be much appreciated. Thanks for your time. Meg Mara
