问题
Working on an Android and iOS based application which require communication with a server running in the same device. Currently using TCP loopback connection for communicating with App and Server (App written in user layer, server written in C++ using Android NDK)
I was wondering if replacing inter communication with Unix Domain socket would improve the performance?
Or in-general is there any evidence/theory that proves that Unix Domain socket would give better performance then TCP loopback connection?
回答1:
Yes, local interprocess communication by unix domain sockets should be faster than communication by loopback localhost connections because you have less TCP overhead, see here.
回答2:
This benchmark: https://github.com/rigtorp/ipc-bench provides latency and throughput tests for TCP sockets, Unix Domain Sockets (UDS), and PIPEs.
Here you have the results on a single CPU 3.3GHz Linux machine :
TCP average latency: 6 us
UDS average latency: 2 us
PIPE average latency: 2 us
TCP average throughput: 0.253702 million msg/s
UDS average throughput: 1.733874 million msg/s
PIPE average throughput: 1.682796 million msg/s
66% latency reduction and almost 7X more throughput explain why most performance-critical software has their own IPC custom protocol.
回答3:
Redis benchmark shows unix domain socket can be significant faster than TCP loopback.
When the server and client benchmark programs run on the same box, both the TCP/IP loopback and unix domain sockets can be used. Depending on the platform, unix domain sockets can achieve around 50% more throughput than the TCP/IP loopback (on Linux for instance). The default behavior of redis-benchmark is to use the TCP/IP loopback.
However, this difference only matters when throughput is high.
回答4:
Unix domain sockets are often twice as fast as a TCP socket when both peers are on the same host. The Unix domain protocols are not an actual protocol suite, but a way of performing client/server communication on a single host using the same API that is used for clients and servers on different hosts. The Unix domain protocols are an alternative to the interprocess communication (IPC) methods.
来源：https://stackoverflow.com/questions/14973942/tcp-loopback-connection-vs-unix-domain-socket-performance