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> 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> 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> 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? >>>> >>>
