[CASSANDRA-5239] Asynchronous (non-blocking) StorageProxy

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Won't Fix
• Labels: performance
• Assignee: Unassigned
• Reporter: Vijay
• Created: 10/Feb/13 22:51
• Updated: 16/Apr/19 09:32
• Resolved: 18/Mar/16 14:23

Description

Problem Statement:

Currently we have "rpc_min_threads, rpc_max_threads"/ "native_transport_min_threads/native_transport_max_threads" all of the threads in the TPE are blocking and takes resources, the threads are mostly sleeping. Increasing the Context switch costs.

Details:

We should change StorageProxy methods to provide a callback which contains the location where the results has to be written. When the response arrive StorageProxy callback can write the results directly into the connection. Timeouts can be handled in the same way.

Fixing Netty should be trivial with some refactor in the storage proxy (currently it is one method call for sending the request and waiting) we need callback.

Fixing Thrift may be harder because thrift calls the method and expects a return value. We might need to write a custom Codec on Netty for thrift support, which can potentially do callbacks (A Custom codec may be similar to http://engineering.twitter.com/2011/04/twitter-search-is-now-3x-faster_1656.html but we dont know details about it). Another option is to update thrift to have a callback.

FYI, The motivation for this ticket is from another project which i am working on with similar Proxy (blocking Netty transport) and making it Async gave us 2x throughput improvement.

Issue Links

• blocks: CASSANDRA-8075 Make netty pipeline fully async
• contains: CASSANDRA-8075 Make netty pipeline fully async
• is superceded by: CASSANDRA-10993 Make read and write requests paths fully non-blocking, eliminate related stages
• relates to: CASSANDRA-8440 Refactor StorageProxy