We migrated one of the application from on-Prem to aws; the queries are very light, more like registration info;
Queries from the new app is via pk of data type, “text”, no cc (this table has about 200 rows; however the legacy table (more like reference table) has several million rows, about 800 sstables per node, using lcs (9:1, read-write ratio) Subroto > On Feb 1, 2019, at 10:33 AM, Kenneth Brotman <kenbrot...@yahoo.com.invalid> > wrote: > > Do you have that many queries? You could just review them and your data > model to see if there was an error of some kind. How long has it been > happening? What changed since it started happening? > > Kenneth Brotman > > From: Subroto Barua [mailto:sbarua...@yahoo.com.INVALID] > Sent: Friday, February 01, 2019 10:13 AM > To: user@cassandra.apache.org > Subject: Re: Help with sudden spike in read requests > > Vnode is 256 > C*: 3.0.15 on m4.4xlarge gp2 vol > > There are 2 more DCs on bare metal (raid 10 and older machines) attached to > this cluster and we have not seen this behavior on on-prem servers > > If this event is triggered by some bad query/queries, what is the best way to > trap it? > > Subroto > > On Feb 1, 2019, at 8:55 AM, Kenneth Brotman <kenbrot...@yahoo.com.invalid> > wrote: > > If you had a query that went across the partitions and especially if you had > vNodes set high, that would do it. > > Kenneth Brotman > > From: Subroto Barua [mailto:sbarua...@yahoo.com.INVALID] > Sent: Friday, February 01, 2019 8:45 AM > To: User cassandra.apache.org > Subject: Help with sudden spike in read requests > > In our production cluster, we observed sudden spike (over 160 MB/s) in read > requests on *all* Cassandra nodes for a very short period (less than a min); > this event happens few times a day. > > I am not able to get to the bottom of this issue, nothing interesting in > system.log or from app level; repair was not running > > Does anyone have any thoughts on what could have triggered this event? Under > what condition C* (if it is tied to c*) will trigger this type of event? > > Thanks! > > Subroto
