clientconn_test

gRPC client connection test

How to maximize the client concurrency.

3 ways

1. One connection per request
   Create a connection when request is made.
2. Only one client, one connection
   Use a common client by all requests.
3. Fixed-size Connection pool
   If connection pool has enough connections, take it from pool, otherwise create a new connection. The connection pool has fixed max capacity, release unused connection to pool when it's not full.

Performance Comparison(Local Computer)

Hardware MacBook Pro (15-inch, 2016)
Processor 2.7 GHz Intel Core i7
Memory 16GB 2133 MHz LPDDR3

Press tool, client and server run on the same machine

Server just says hello to client

1. Only one client, one connection

   $ wrk -t2 -c100 -d10s http://localhost:10099/performance
   Running 10s test @ http://localhost:10099/performance
     2 threads and 100 connections
     Thread Stats   Avg      Stdev     Max   +/- Stdev
       Latency     2.85ms    1.24ms  22.24ms   80.47%
       Req/Sec    15.86k     2.86k   21.58k    76.50%
     316674 requests in 10.04s, 38.66MB read
   Requests/sec:  31532.58
   Transfer/sec:      3.85MB

2. Fixed-size Connection pool
   Take connection from pool first, otherwise create a new connection.

   $ wrk -t2 -c100 -d10s http://localhost:10099/performance
   Running 10s test @ http://localhost:10099/performance
     2 threads and 100 connections
     Thread Stats   Avg      Stdev     Max   +/- Stdev
       Latency    36.86ms   34.35ms 334.72ms   83.30%
       Req/Sec     1.58k   660.95     3.89k    67.86%
     31127 requests in 10.04s, 3.80MB read
   Requests/sec:   3100.89
   Transfer/sec:    387.61KB

3. One connection per request
   Close to the second result, about 3000 Requests/sec

Server sleeps 0.5s and says hello to client

1. Only one client, one connection

   $ wrk -t2 -c100 -d10s http://localhost:10099/performance
   Running 10s test @ http://localhost:10099/performance
     2 threads and 100 connections
     Thread Stats   Avg      Stdev     Max   +/- Stdev
       Latency   503.43ms    1.95ms 511.62ms   64.35%
       Req/Sec   130.60    119.12   485.00     80.85%
     2000 requests in 10.10s, 250.00KB read
   Requests/sec:    198.04
   Transfer/sec:     24.75KB

2. Fixed-size Connection pool

   $ wrk -t2 -c100 -d10s http://localhost:10099/performance
   Running 10s test @ http://localhost:10099/performance
     2 threads and 100 connections
     Thread Stats   Avg      Stdev     Max   +/- Stdev
       Latency   504.44ms    5.14ms 529.46ms   92.58%
       Req/Sec   119.40     95.83   470.00     85.11%
     1901 requests in 10.07s, 237.62KB read
   Requests/sec:    188.80
   Transfer/sec:     23.60KB

3. one connection per request

   $ wrk -t2 -c100 -d10s http://localhost:10099/performance
   Running 10s test @ http://localhost:10099/performance
     2 threads and 100 connections
     Thread Stats   Avg      Stdev     Max   +/- Stdev
       Latency   509.30ms    4.85ms 529.65ms   73.74%
       Req/Sec   188.81    188.12   494.00     71.23%
     1900 requests in 10.06s, 237.50KB read
   Requests/sec:    188.89
   Transfer/sec:     23.61KB