RFR: 8270317: Large Allocation in CipherSuite

[Clive Verghese]

On Wed, 14 Jul 2021 17:06:02 GMT, Clive Verghese <cverghese at openjdk.org> wrote:

> ### Benchmark results 
> 
> I have benchmarked 3 cases.
> 
> 1. The current situation. 
> 
> Benchmark                                                        (cipherSuite)  Mode  Cnt    Score   Error  Units
> CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  124.783 ? 2.050  ns/op
> CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  125.403 ? 0.554  ns/op
> CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  127.117 ? 0.789  ns/op
> CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  127.869 ? 1.112  ns/op
> 
> 
> 2. Use `static final array` instead of calling `CipherSuite.values` each time. 
> 
> Benchmark                                                        (cipherSuite)  Mode  Cnt   Score   Error  Units
> CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  10.146 ? 0.252  ns/op
> CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  30.501 ? 0.207  ns/op
> CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  47.375 ? 0.150  ns/op
> CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  55.887 ? 3.786  ns/op
> 
> 
> 3. Using Hashmap for lookup instead of iterating through the array each time. (Method in this PR)
> 
> Benchmark                                                        (cipherSuite)  Mode  Cnt   Score   Error  Units
> CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  13.533 ? 0.148  ns/op
> CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  11.269 ? 0.147  ns/op
> CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  11.507 ? 0.107  ns/op
> CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  10.932 ? 0.146  ns/op
> 
> 
> I have picked 4 cipher suite from the start of the list and are roughly 10 positions apart. I have opted to go with HashMap for name and id lookup as they provide a more consistent times and benchmarks are similar for the first few cipher suits in the enum as well.

Updated Benchmarks in Throughput mode 

### Current 

Benchmark                                                        (cipherSuite)   Mode  Cnt     Score     Error   Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  thrpt   25  8050.787 ? 232.335  ops/ms
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  thrpt   25  8165.124 ? 283.718  ops/ms
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  thrpt   25  7827.758 ? 293.311  ops/ms
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  thrpt   25  7768.286 ? 181.399  ops/ms


### ArrayList

Benchmark                                                        (cipherSuite)   Mode  Cnt    Score   Error   Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  thrpt   25  100.626 ? 0.294  ops/us
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  thrpt   25   32.793 ? 0.804  ops/us
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  thrpt   25   21.162 ? 0.217  ops/us
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  thrpt   25   18.220 ? 0.903  ops/us


### Hashmap

Benchmark                                                        (cipherSuite)   Mode  Cnt   Score   Error   Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  thrpt   25  63.836 ? 4.517  ops/us
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  thrpt   25  69.983 ? 8.965  ops/us
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  thrpt   25  68.091 ? 7.404  ops/us
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  thrpt   25  52.831 ? 4.317  ops/us


I am currently looking into the JFR profiles to identify why there is a difference in benchmarks with regards the different cipher suits in the current version vs the arraylist.

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PR: https://git.openjdk.java.net/jdk/pull/4783