Congratulation! You've just found out the cause of it. Does all data get
deletes 48 hours after they are inserted? If so, are you sure LCS is the
right compaction strategy for this table? TWCS sounds like a much better
fit for this purpose.
On 17/09/2021 19:16, Abdul Patel wrote:
Thanks.
Application deletes data every 48hrs of older data.
Auto compaction works but as space is full ..errorlog only says not
enough space to run compaction.
On Friday, September 17, 2021, Bowen Song <bo...@bso.ng
<mailto:bo...@bso.ng>> wrote:
If major compaction is failing due to disk space constraint, you
could copy the files to another server and run a major compaction
there instead (i.e.: start cassandra on new server but not joining
the existing cluster). If you must replace the node, at least use
the '-Dcassandra.replace_address=...' parameter instead of
'nodetool decommission' and then re-add, because the later changes
the token ranges on the node, and that makes troubleshooting harder.
22GB of data amplifies to nearly 300GB sounds very impossible to
me, there must be something else going on. Have you turned off
auto compaction? Did you change the default parameters (namely,
the 'fanout_size') for LCS? If this doesn't give you a clue, have
a look at the SSTable data files, do you notice anything unusual?
For example, too many small files, or some files are
extraordinarily large. Also have a look at the logs, is there
anything unusual? Also, do you know the application logic? Does it
do a lots of delete or update (including 'upsert')? Writes with
TTL? Does the table has a default TTL?
On 17/09/2021 13:45, Abdul Patel wrote:
Close 300 gb data. Nodetool decommission/removenode and added
back one node ans it came back to 22Gb.
Cant run major compaction as no space much left.
On Friday, September 17, 2021, Bowen Song <bo...@bso.ng
<mailto:bo...@bso.ng>> wrote:
Okay, so how big exactly is the data on disk? You said
removing and adding a new node gives you 20GB on disk, was
that done via the '-Dcassandra.replace_address=...'
parameter? If not, the new node will almost certainly have a
different token range and not directly comparable to the
existing node if you have uneven partitions or small number
of partitions in the table. Also, try major compaction, it's
a lot easier than replacing a node.
On 17/09/2021 12:28, Abdul Patel wrote:
Yes i checked and cleared all snapshots and also i had
incremental backups in backup folder ..i removed the same ..
its purely data..
On Friday, September 17, 2021, Bowen Song <bo...@bso.ng
<mailto:bo...@bso.ng>> wrote:
Assuming your total disk space is a lot bigger than 50GB
in size (accounting for disk space amplification, commit
log, logs, OS data, etc.), I would suspect the disk
space is being used by something else. Have you checked
that the disk space is actually being used by the
cassandra data directory? If so, have a look at
'nodetool listsnapshots' command output as well.
On 17/09/2021 05:48, Abdul Patel wrote:
Hello
We have cassandra with leveledcompaction strategy,
recently found filesystem almost 90% full but the
data was only 10m records.
Manual compaction will work? As not sure its
recommended and space is also constraint ..tried
removing and adding one node and now data is at 20GB
which looks appropropiate.
So is only solution to reclaim space is remove/add node?
