CODEWITHSUNDEEP
cassandradatastax
Raw_man
Raw_man

Reputation: 19

Cassandra - SSTable Readpth & Write Path

Hello Cassandra specialists!!!

How will go about analyzing Read path and Write path for Cassandra? Basically, I would like to know what is read path and write path measurements and if i give some sample row keys , how will I know, how many SStables are there currently for that particular Row Key and where is that located about details? Based on this detail I would like know what is causing slowness and for read path and what can be improved. I am particularly interested in knowing How many SSTables are there for particular RowKey and where they are located? This is one of the POC that I am working on for the client. Thanks in advance...

Upvotes: 1

Views: 903

Answers (2)

user3851435
user3851435

Reputation: 21

Another possible mechanism could be to use nodetool getsstables <keyspace><cf><key which will give you the list of sstables which contain the key.

Another option is to write a script which sort of runs/repeats the sstable2json on all the files in the folder and greps for the specific key. Once the key is found, you can write that file into some sort of datastructure and then later obtain the details of the same from the datastructure.

Upvotes: 2

Lyuben Todorov
Lyuben Todorov

Reputation: 14153

The Docs tend to be a good starting point:

how will I know, how many SStables are there currently for that particular Row Key

You can use sstable2json to view the raw information contained within sstables in a json format and hunt down particular keys to see how they are distributed across replicas. This will be fiddly especially if you have a lot of sstables, so you can use nodetool getendpoints <keyspace> <table> <key> to workout which node actually owns the key and then start converting sstables to json.

Upvotes: 1

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