[THRIFT-3084] C++ add concurrent client limit to threaded servers

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8, 0.9, 0.9.1, 0.9.2
• Fix Version/s: 0.9.3
• Component/s: C++ - Library
• Assignee: James E. King III
• Reporter: James E. King III
• Created: 05/Apr/15 13:18
• Updated: 01/Feb/19 05:44
• Resolved: 04/May/15 13:40

Description

The TThreadedServer and TThreadPoolServer do not impose limits on the number of simultaneous connections, which is not useful in production as bad clients can drive a server to consume too many file descriptors or have too many threads.

With TThreadPoolServer one can set the limit on the number of threads, however the server will use one additional file descriptor because the serve() routine does not block until after accepting the threadManager size + 1 sockets.

With TThreadedServer there was no built-in way to throttle.

Give the serve() loop is the only code capable of adding a client, the solution is to add a Monitor to the TServerFramework and check the number of concurrent clients immediately before calling TServerTransport::accept() to get another client, and to track the number of clients that are still alive (their smart pointer hasn't been destroyed).

Issue Links

• is blocked by: THRIFT-3083 C++ Consolidate server processing loops in TSimpleServer, TThreadedServer, TThreadPoolServer
• is related to: THRIFT-3970 Server does not limititate client connections
• relates to: THRIFT-3096 Consolidate TSimpleServer, TThreadedServer, TThreadPoolServer into one