Hi Asad, You can increase it by 2 at a time. For example if its currently 2, try increasing it to 4 and retest. We flush 5-6 tables at a time and use 3 memtable_flush_writers. It works great!! There were dropped mutations when it was set to one. The idea is to make sure that writes are not blocked. ThanksAnuj Sent from Yahoo Mail on Android On Fri, 21 Jul 2017 at 20:04, ZAIDI, ASAD A<az1...@att.com> wrote: #yiv0831784205 #yiv0831784205 -- _filtered #yiv0831784205 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv0831784205 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}#yiv0831784205 #yiv0831784205 p.yiv0831784205MsoNormal, #yiv0831784205 li.yiv0831784205MsoNormal, #yiv0831784205 div.yiv0831784205MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}#yiv0831784205 a:link, #yiv0831784205 span.yiv0831784205MsoHyperlink {color:blue;text-decoration:underline;}#yiv0831784205 a:visited, #yiv0831784205 span.yiv0831784205MsoHyperlinkFollowed {color:purple;text-decoration:underline;}#yiv0831784205 p.yiv0831784205msonormal, #yiv0831784205 li.yiv0831784205msonormal, #yiv0831784205 div.yiv0831784205msonormal {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv0831784205 p.yiv0831784205msochpdefault, #yiv0831784205 li.yiv0831784205msochpdefault, #yiv0831784205 div.yiv0831784205msochpdefault {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv0831784205 span.yiv0831784205msohyperlink {}#yiv0831784205 span.yiv0831784205msohyperlinkfollowed {}#yiv0831784205 span.yiv0831784205emailstyle17 {}#yiv0831784205 p.yiv0831784205msonormal1, #yiv0831784205 li.yiv0831784205msonormal1, #yiv0831784205 div.yiv0831784205msonormal1 {margin:0in;margin-bottom:.0001pt;font-size:11.0pt;}#yiv0831784205 span.yiv0831784205msohyperlink1 {color:#0563C1;text-decoration:underline;}#yiv0831784205 span.yiv0831784205msohyperlinkfollowed1 {color:#954F72;text-decoration:underline;}#yiv0831784205 span.yiv0831784205emailstyle171 {color:windowtext;}#yiv0831784205 p.yiv0831784205msochpdefault1, #yiv0831784205 li.yiv0831784205msochpdefault1, #yiv0831784205 div.yiv0831784205msochpdefault1 {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv0831784205 span.yiv0831784205EmailStyle27 {color:#1F497D;}#yiv0831784205 .yiv0831784205MsoChpDefault {} _filtered #yiv0831784205 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv0831784205 div.yiv0831784205WordSection1 {}#yiv0831784205 Thank you for your reply. I’ll increase memTable_flush_writes and report back if it helps. Is there any formula that we can use to arrive at correct number of memTable_flush_writers ? or the exercise would windup be like “try and error” taking much time to arrive at some number that may not be optimal. Thank you again. From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Thursday, July 20, 2017 12:17 PM To: ZAIDI, ASAD A <az1...@att.com>; user@cassandra.apache.org Subject: Re: MUTATION messages were dropped in last 5000 ms for cross node timeout Hi Asad, You can do following things: 1.Increase memtable_flush_writers especially if you have a write heavy load. 2.Make sure there are no big gc pauses on your nodes. If yes, go for heap tuning. Please let us know whether above measures fixed your problem or not. Thanks Anuj Sent from Yahoo Mail on Android
On Thu, 20 Jul 2017 at 20:57, ZAIDI, ASAD A <az1...@att.com> wrote: Hello Folks – I’m using apache-cassandra 2.2.8. I see many messages like below in my system.log file. In Cassandra.yaml file [ cross_node_timeout: true] is set and NTP server is also running correcting clock drift on 16node cluster. I do not see pending or blocked HintedHandoff in tpstats output though there are bunch of MUTATIONS dropped observed. <start timeout message > INFO [ScheduledTasks:1] 2017-07-20 08:02:52,511 MessagingService.java:946 - MUTATION messages were dropped in last 5000 ms: 822 for internal timeout and 2152 for cross node timeout <end timeout message > I’m seeking help here if you please let me know what I need to check in order to address these cross node timeouts. Thank you, Asad