CODEWITHSUNDEEP
cassandracassandra-2.1
Laxmikant
Laxmikant

Reputation: 1621

Is there any way to differentiate sessions of each client in cassandra QueryHandler?

My aim is to log unique queries per session by writing custom QueryHandler implementation as logging all queries causes performance hit in our case.

Consider the case : If a user connected to cassandra cluster with java client and performs "select * from users where id = ?" 100 times. And another user connected from cqlsh and performed same query 50 times. so i want to log only two queries in this case. For that i need a unique session id per login.

Cassandra provides below interface where all requests lands up but none of its apis provide any sessionId to differentiate between two different session described in above case.

org.apache.cassandra.cql3.QueryHandler

Note: I am able to get remoteaddress/port but i want some id which is created when user logged in and get destroyed when he disconnects.

Upvotes: 0

Views: 437

Answers (1)

Chris Lohfink
Chris Lohfink

Reputation: 16410

In queryState.getClientState().getRemoteAddress() the address + port will be unique per tcp connection in the sessions pool. There can be multiple concurrent requests over each connection though, and a session can have multiple connections per host. There is also no guarantee the same tcp connection will be used from one request to another on client side.

However a single session cannot be connected as 2 different users (part of the initialization of connection) so the scenario you described isn't possible from the same Session object perspective. I think just using the address as the key for uniqueness will be all you can do given how the protocol/driver works. It will at least dedup things a little.

Are you actually processing your logging inline or are you pushing it off async? If using logback it should be using async appender but if your posting events synchronously to another server, might be better just to throw all the events on a queue and let it do the deduping in another thread so you don't hurt latency.

Upvotes: 1

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