It is observed in a local 8 drive system the CPU seems to be
bottlenecked at
```
(pprof) top
Showing nodes accounting for 1385.31s, 88.47% of 1565.88s total
Dropped 1304 nodes (cum <= 7.83s)
Showing top 10 nodes out of 159
flat flat% sum% cum cum%
724s 46.24% 46.24% 724s 46.24% crypto/sha256.block
219.04s 13.99% 60.22% 226.63s 14.47% syscall.Syscall
158.04s 10.09% 70.32% 158.04s 10.09% runtime.memmove
127.58s 8.15% 78.46% 127.58s 8.15% crypto/md5.block
58.67s 3.75% 82.21% 58.67s 3.75% github.com/minio/highwayhash.updateAVX2
40.07s 2.56% 84.77% 40.07s 2.56% runtime.epollwait
33.76s 2.16% 86.93% 33.76s 2.16% github.com/klauspost/reedsolomon._galMulAVX512Parallel84
8.88s 0.57% 87.49% 11.56s 0.74% runtime.step
7.84s 0.5% 87.99% 7.84s 0.5% runtime.memclrNoHeapPointers
7.43s 0.47% 88.47% 22.18s 1.42% runtime.pcvalue
```
Bonus changes:
- re-use transport for bucket replication clients, also site replication clients.
- use 32KiB buffer for all read and writes at transport layer seems to help
TLS read connections.
- Do not have 'MaxConnsPerHost' this is problematic to be used with net/http
connection pooling 'MaxIdleConnsPerHost' is enough.
- currently subnet health check was freezing and calling
locks at multiple locations, avoid them.
- throw errors if first attempt itself fails with no results