Estimates how parallel batches count affects load time of same amount of persistent data.
The lesser score (average load time), the better.

Larger data to load compared to other benchmarks for longer test to be sure and with FSYNC WAL.

Results in short: looks like 1 batch per thread is enough. But we can keep x2 for network issues.

servers - server nodes
maxDsOps - streamer's batches per node
sendMsgDelay - simulated network delay or write responses.

==================================================================================================================================================================
Benchmark                                                    (cacheWriteMode)  (maxDsOps)  (sendMsgDelay)  (servers)  (walMode)  Mode  Cnt   Score    Error  Units

SERVERS: 3
>>> [Same load time]
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated      PRIMARY_SYNC          16               3          3      FSYNC  avgt    5  73,304 ± 7,379   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated      PRIMARY_SYNC          32               3          3      FSYNC  avgt    5  71,660 ± 12,977   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated      PRIMARY_SYNC          64               3          3      FSYNC  avgt    5  69,855 ± 17,046   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated      PRIMARY_SYNC         128               3          3      FSYNC  avgt    5  69,760 ± 16,378   s/op
=== FULL_SYNC:
>>> [Same load time]
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated         FULL_SYNC          16               3          3      FSYNC  avgt    5  74,296 ± 5,932   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated         FULL_SYNC          32               3          3      FSYNC  avgt    5  58,696 ± 12,019   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated         FULL_SYNC          64               3          3      FSYNC  avgt    5  72,845 ± 10,253   s/op
JmhPersistentStreamerReceiverBenchmark.benchDefaultIsolated         FULL_SYNC         128               3          3      FSYNC  avgt    5  70,263 ±  8,201   s/op
==================================================================================================================================================================

OS: Linux void 5.18.0-4-amd64 #1 SMP PREEMPT_DYNAMIC Debian 5.18.16-1 (2022-08-10) x86_64 GNU/Linux

JMH 1.13
VM version: JDK 11.0.2, VM 11.0.2+9
VM options: -Xms2g -Xmx2g -server -XX:+AlwaysPreTouch

CPU:
vendor_id       : AuthenticAMD
cpu family      : 25
model           : 80
model name      : AMD Ryzen 7 5800U with Radeon Graphics
cpu MHz         : 1600.000
cache size      : 512 KB
siblings        : 16
cpu cores       : 8
cpuid level     : 16

Disk:
`dd if=/dev/zero of=/tmp/test1.img bs=1G count=1 oflag=dsync`: 1073741824 bytes (1,1 GB, 1,0 GiB) copied, 1,25661 s, 854 MB/s
`dd if=/dev/zero of=/tmp/test2.img bs=512 count=1000 oflag=dsync`: 512000 bytes (512 kB, 500 KiB) copied, 2,80265 s, 183 kB/s