Stabilize performances: using ZStream.DefaultChunkSize as the commandQueueSize stabilize benchmarks performances

[guizmaii]

Before (See #751):

[info] # Fork: 5 of 5
[info] OpenJDK 64-Bit Server VM warning: -XX:ThreadPriorityPolicy=1 may require system level permission, e.g., being the root user. If the necessary permission is not possessed, changes to priority will be silently ignored.
[error] SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
[error] SLF4J: Defaulting to no-operation (NOP) logger implementation
[error] SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
[error] SLF4J: Failed to load class "org.slf4j.impl.StaticMDCBinder".
[error] SLF4J: Defaulting to no-operation MDCAdapter implementation.
[error] SLF4J: See http://www.slf4j.org/codes.html#no_static_mdc_binder for further details.
[info] # Warmup Iteration   1: 2049.754 ms/op
[info] # Warmup Iteration   2: 1481.757 ms/op
[info] # Warmup Iteration   3: 1578.479 ms/op
[info] # Warmup Iteration   4: 4836.508 ms/op
[info] # Warmup Iteration   5: 1980.513 ms/op
[info] # Warmup Iteration   6: 4928.249 ms/op
[info] # Warmup Iteration   7: 1472.769 ms/op
[info] # Warmup Iteration   8: 1263.501 ms/op
[info] # Warmup Iteration   9: 5014.016 ms/op
[info] # Warmup Iteration  10: 1258.164 ms/op
[info] Iteration   1: 1958.565 ms/op
[info] Iteration   2: 1735.329 ms/op
[info] Iteration   3: 1414.613 ms/op
[info] Iteration   4: 1224.270 ms/op
[info] Iteration   5: 1404.372 ms/op
[info] Iteration   6: 1236.202 ms/op
[info] Iteration   7: 3817.833 ms/op
[info] Iteration   8: 3835.710 ms/op
[info] Iteration   9: 1841.279 ms/op
[info] Iteration  10: 1332.895 ms/op
[info] Result "zio.kafka.bench.ConsumersComparisonBenchmark.zioKafka":
[info]   1636.533 ±(99.9%) 402.992 ms/op [Average]
[info]   (min, avg, max) = (783.816, 1636.533, 4721.287), stdev = 814.063
[info]   CI (99.9%): [1233.541, 2039.525] (assumes normal distribution)
[info] # Run complete. Total time: 00:07:09

After:

[info] # Fork: 5 of 5
[info] OpenJDK 64-Bit Server VM warning: -XX:ThreadPriorityPolicy=1 may require system level permission, e.g., being the root user. If the necessary permission is not possessed, changes to priority will be silently ignored.
[info] # Warmup Iteration   1: 02:51:19.096 [ZScheduler-Worker-2] WARN  k.server.BrokerMetadataCheckpoint - No meta.properties file under dir /var/folders/5r/0tttbjvx405d9c4pg69m6swh0000gn/T/kafka-logs7980195044750925851/meta.properties
[info] 2863.312 ms/op
[info] # Warmup Iteration   2: 2547.039 ms/op
[info] # Warmup Iteration   3: 2602.239 ms/op
[info] # Warmup Iteration   4: 1612.479 ms/op
[info] # Warmup Iteration   5: 1407.847 ms/op
[info] # Warmup Iteration   6: 1285.473 ms/op
[info] # Warmup Iteration   7: 1271.330 ms/op
[info] # Warmup Iteration   8: 2575.500 ms/op
[info] # Warmup Iteration   9: 1752.090 ms/op
[info] # Warmup Iteration  10: 1870.162 ms/op
[info] Iteration   1: 1032.892 ms/op
[info] Iteration   2: 1067.703 ms/op
[info] Iteration   3: 1452.908 ms/op
[info] Iteration   4: 1332.049 ms/op
[info] Iteration   5: 1853.705 ms/op
[info] Iteration   6: 1441.071 ms/op
[info] Iteration   7: 1220.899 ms/op
[info] Iteration   8: 1213.413 ms/op
[info] Iteration   9: 2371.653 ms/op
[info] Iteration  10: 1157.814 ms/op
[info] Result "zio.kafka.bench.ConsumersComparisonBenchmark.zioKafka":
[info]   1563.992 ±(99.9%) 397.705 ms/op [Average]
[info]   (min, avg, max) = (953.422, 1563.992, 4827.394), stdev = 803.384
[info]   CI (99.9%): [1166.287, 1961.697] (assumes normal distribution)
[info] # Run complete. Total time: 00:07:00

[guizmaii]

Not proven enough by bench results