Currently I am debugging performance issue with Apache Cassandra. when Memtable for the column family is filled, it is queued to be flushed to SSTable. This flushing happens often when you perform massive writes. When this queue is filled up, writes are blocked until next successful completion of flush. This indicates that your node cannot handle writes it is receiving.
Is there a matrix in nodetool indicating this behaviour? In other words, I want a data indicating a node cannot keep up with writes it is receiving.
Thanks!!
I want a data indicating a node cannot keep up with writes it is receiving.
Your issue is likely bound to disk I/O not being able to handle the throughput --> flushes of memtables queue up --> writes are blocked
the command dstat is your friend to investigate I/O issues. Some others linux commands may be also handy. Read this excellent blog post from Amy Tobey: https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html
Is there a matrix in nodetool indicating this behaviour?
nodetool tpstats