cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Meg Mara <mm...@digitalriver.com>
Subject RE: Tombstone warnings in log file
Date Mon, 04 Dec 2017 17:54:42 GMT
Simon,

It means that in processing your queries, Cassandra is going through that many tombstone cells
in order to return your results. It is because some of the partitions that you are querying
for have already expired. The warning is just cassandra's way of letting you know that your
reads are less efficient because you are reading a lot of expired data.

You could tune this by altering your tombstone parameters in Cassandra yaml file. But a better
solution would be to reduce your GC grace seconds for that table to a smaller value (as opposed
to default of 10 days) so that the TTLed data will be purged sooner.

You could also consider drafting more efficient queries which won't hit TTLed partitions.

Thanks,
Meg


From: wxn002@zjqunshuo.com [mailto:wxn002@zjqunshuo.com]
Sent: Sunday, December 03, 2017 7:49 PM
To: user <user@cassandra.apache.org>
Subject: Tombstone warnings in log file

Hi,
My cluster is running 2.2.8, no update and deletion, only insertion with TTL.  I saw below
warnings reacently. What's the meaning of them and what's the impact?

WARN  [SharedPool-Worker-2] 2017-12-04 09:32:48,833 SliceQueryFilter.java:308 - Read 2461
live and 1978 tombstone cells in cargts.eventdata for key: 129762:20171202 (see tombstone_warn_threshold).
5000 columns were requested, slices=[-]


Best regards,
-Simon

WARN  [SharedPool-Worker-2] 2017-12-04 09:32:48,833 SliceQueryFilter.java:308 - Read 2461
live and 1978 tombstone cells in cargts.eventdata f        or key: 129762:20171202 (see tombstone_warn_threshold).
5000 columns were requested, slices=[-]

Mime
View raw message