tree 219be94ef34e6a27c95df5dc67acc6b09ce0d5a5
parent 194d1512c07f3fbfc1fc9d6c7e4ff66139b4a70f
author Kun Zhang <zhangkun83@users.noreply.github.com> 1573775411 -0800
committer GitHub <noreply@github.com> 1573775411 -0800
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netty: provide an option to lower netty allocator chunk size from 16MB to 2MB (#6407)

This would reduce the amount of direct buffer allocations, especially with light traffic. This should mitigate internal issue b/143075435

The change is currently optional and is only effective if system property "io.grpc.netty.useCustomAllocator" is set to "true" ignoring the case.

Internal benchmark results (median of 5 runs) doesn't show any significant change:
```
                          Before (STDEV)           After (STDEV)
grpc-java-java-multi-qps-integrity_only
Actual QPS               717,848 (7,445)         715,061 (2,122) 
QPS per Client CPU        23,768   (799)          23,842   (295)

grpc-java-java-multi-throughput-integrity_only
Actual QPS                35,631   (204)          35,298    (25) 
QPS per Client CPU         3,362    (56)           3,316    (18)

grpc-java-java-single-latency-integrity_only
Median latency (us)          130  (1.82)             125  (5.36)

grpc-java-java-single-throughput-integrity_only
Actual QPS                    593 (5.14)             587  (3.76)
QPS per Client CPU            502 (4.51)             494  (6.92)

```