ื ืงืืจืฆืข ืืขืฉื ืืืขืื ืคืืื ืืื ืืื'
ืงื ืืื ืคืึธืจืฉืืขืืื ื
fio --rw=write --ioengine=sync --fdatasync=1 --directory=test-data --size=22m --bs=2300 --name=mytest
ืืืจ ื ืึธืจ ืืึทืจืคึฟื ืฆื ืงืืงื ืืื ืื ืจืขืืืืืึทืื ืืื ืงืึธื ืืจืึธืืืจื ืึทื ืื 99 ืคึผืจืึธืฆืขื ื ืคืื ืื ืืขืืืืขืจ
sync (usec): min=534, max=15766, avg=1273.08, stdev=1084.70
sync percentiles (usec):
| 1.00th=[ 553], 5.00th=[ 578], 10.00th=[ 594], 20.00th=[ 627],
| 30.00th=[ 709], 40.00th=[ 750], 50.00th=[ 783], 60.00th=[ 1549],
| 70.00th=[ 1729], 80.00th=[ 1991], 90.00th=[ 2180], 95.00th=[ 2278],
| 99.00th=[ 2376], 99.50th=[ 9634], 99.90th=[15795], 99.95th=[15795],
| 99.99th=[15795]
ืืขืจืืช
- ืืืจ ืืึธืื ืงืึทืกืืึทืืืืื ืื -- ืืจืืืก ืืื --bs ืึธืคึผืฆืืขืก ืคึฟืึทืจ ืืื ืืืขืจ ืืึทืืื ืืขืจ ืกืฆืขื ืึทืจ. ืฆื ืืึทืงืืืขื ืึท ื ืืฆืืง ืจืขืืืืืึทื ืคืื fio, ืฆืืฉืืขืื ืืืื ืืืืืขื ืข ืืืึทืืืขืก. ืืื ืฆื ืืึทืงืืืขื ืืื? ืืืืขื ืขื
ืืื ืืืจ ืืขืืขืจื ื ืฆื ืงืึทื ืคืืืืขืจ ืคืืึธ . - ืืขืฉืึทืก ืืขืกืืื ื, ืึทืืข ื / ืึธ ืืึทืกืข ืงืืื ืคึฟืื ืคืืึธ. ืืื ืึท ืคืึทืงืืืฉ-ืืขืื ืกืฆืขื ืึทืจ, ืขืก ืืืขื ืืกืชึผืื ืืืื ืื ืืขืจืข ืฉืจืืึทืื ืจืืงืืืขืก ืงืืืขื ืืื ืื ืกืืึธืจืืืืฉ ืึทืืืฅ ืื ืฉืืึทืืืช ืฆื wal_fsync_duration_seconds. ืื ืขืงืกืืจืข ืืึทืกืข ืืืขื ืคืึทืจืืจืขืกืขืจื ืื ืืืขืจื ืคืื wal_fsync_duration_seconds. ืึทืืื ืืืื ืื 99 ืคึผืขืจืกืขื ืืื ืืื ื ืึธืขื ื ืฆื 10ms, ืืืื ืกืืึธืจืืืืฉ ืืื ืคืืืกื ืืืง ืืืืก ืคืื ืืืืงืืึทื.
- ื ืขืืขื ืื ืืืขืจืกืืข
fio ื ืื ื ืืืขืจืืงืขืจ ืืื 3.5 (ืื ืคืจืืขืจืืืงืข ืึธื ืขืก ืืึธื ื ืื ืืืืึทืื ืคืืึทืืึทืกืื ืง ืืขืืืืขืจ ืคึผืขืจืกืขื ืืืืื). - ืืืืื ืืื ืืืืื ืึท ืกื ืืคึผืึทื ืคืื ืื ืจืขืืืืืึทืื ืคืื ืคืืึธ.
ืืื ืืข ืืขืฉื ืืืขืื ืคืืื ืืื ืืื'
ืืืึธืก ืืื WAL ืืื ืขืืง
ืืกืืึทืืื ืืึทืืึทืืืืกืื ื ืืฆื
ืืืขื ืึท ืงืืืขื ื ืืืกืืฃ ืึท ืฉืืืกื ืฆื ืื ืฉืืืกื / ืืืขืจื ืงืจืึธื ืึธืืขืจ ืืขืจืืืึทื ืืืงื ืื ืืืขืจื ืคืื ืึท ืืืืืกืืื ื ืฉืืืกื, ืขืืง ืจืขืงืึธืจืืืจื โโโโืื ืึธืคึผืขืจืึทืฆืืข ืืื WAL, ืืืึธืก ืืื ืึท ืจืขืืืืขืจ ืืขืงืข ืืื ืคึผืขืจืกืืกืืขื ื ืกืืึธืจืืืืฉ. etcd ืืืื ืืืื ืืึธืจ ืืืืขืจ ืึทื ืื WAL ืคึผืึธืืืฆืืข ืืื ืึทืงืฉืื ืคืืจืืขืงืืืขื ืืืืืขืจ ืคืึธืจืืขืฆื ืืื ืคึผืจืึทืกืขืกืื ื. ืืืืฃ ืืื ืืงืก, ืืืื ืกืืกืืขื ืจืืคื ืืื ื ืืฉื ืืขื ืื ืคึฟืึทืจ ืืขื.
21:23:09.894875 lseek(8, 0, SEEK_CUR) = 12808 <0.000012>
21:23:09.894911 write(8, ". 20210220361223255266632$10 20103026"34"rn3fo"..., 2296) = 2296 <0.000130>
21:23:09.895041 fdatasync(8) = 0 <0.008314>
ืฆืื ืืึทืืืืขืจื, ืฉืจืืืื ืฆื ืคึผืขืจืกืืกืืขื ื ืกืืึธืจืืืืฉ ืืื ื ืืฉื ืคึผืึทืกืืจื ืืืืงืขืฃ. ืืืื ืื fdatasync ืจืืคื ืืื ืคึผืึทืืขืืขื, ืื ืคืึธืจืฉืืขืืื ื ืคืื ืื ืขืืง ืกืืกืืขื ืืืขื ืืืึทืื.
ืขืกืืืืึทืืขื ืกืืึธืจืืืืฉ ืืื ืคืืึธ
ืืืื ืืืจ ืืึทืจืคึฟื ืฆื ืึธืคึผืฉืึทืฆื ืืืื ืืืื ืกืืึธืจืืืืฉ ืืื ืคึผืึทืกืืง ืคึฟืึทืจ ืขืืง, ื ืืฆื fio, ืึท ืืืืขืจ ืคืึธืืงืก I/O ืืึทืกืข ืืขืกืืื ื ืืขืฆืืึทื. ืขืก ืืึธื ืืืื ืืขืจืืื ื ืึทื ืืืกืง ืึทืคึผืขืจืืืฉืึทื ื ืงืขื ืขื ืืืื ืืืืขืจ ืึทื ืืขืจืฉ: ืกืื ืืฉืจืึธื ืึธืืก ืืื ืืืกืื ืืงืจืึทื ืึทืก, ืคืืืข ืงืืืกื ืคืื ืกืืกืืขื ืงืึทืืืก, ืืื"ื ื. ืืื ืึท ืจืขืืืืืึทื, ืคืืึธ ืืื ืืึทื ืฅ ืฉืืืขืจ ืฆื ื ืืฆื. ืขืก ืืื ืคืืืข ืคึผืึทืจืึทืืขืืขืจืก, ืืื ืคืึทืจืฉืืืขื ืข ืงืึทืืืึทื ืืืฉืึทื ื ืคืื ืืืืขืจ ืืืึทืืืขืก ืคึผืจืึธืืืฆืืจื ืืืืขืจ ืคืึทืจืฉืืืขื ืข ื / ืึธ ืืืขืจืงืืึธืืื. ืฆื ืืึทืงืืืขื ืืืืื ืคืืืืขืจื ืคึฟืึทืจ ืขืืง, ืืืจ ืืึธื ืืึทืื ืืืืขืจ ืึทื ืื ืคึผืจืึธืืข ืฉืจืืึทืื ืืึทืกืข ืคืื โโืคืืึธ ืืื ืืื ื ืึธืขื ื ืืื ืืขืืืขื ืฆื ืื ืคืึทืงืืืฉ ืืึทืกืข ืคืื โโืขืืง ืืืขื ืฉืจืืืื WAL ืืขืงืขืก.
ืืขืจืืืขืจ, ืคืืึธ ืืึธื, ืืืึท ืึท ืืื ืืืื, ืืึทืื ืึท ืืึทืกืข ืืื ืื ืคืึธืจืขื ืคืื ืึท ืกืขืจืืข ืคืื โโโโืงืึทื ืกืขืงืืืืืืข ืฉืจืืืื ืฆื ืืขืจ ืืขืงืข, ืืขืืขืจ ืฉืจืืึทืื ืืืขื ืฆืื ืืืคืฉืืขืื ืืื ืคืื ืึท ืกืืกืืขื ืจืืคื
ืคืืจืืืืก ืคึผืื ืงื ืคืืึธ ืืื ืืื ืืืจ ืืขืืขืจื ื ืฆื ืฉืืขืื ืขืก ืึทืจืืืฃ
ืืื ืืขื ืคึผืึธืกืื, ืืืจ ืืึทืฉืจืืึทืื ืึท ืคืึทืงืืืฉ ืคืึทื. ืืืจ ืืึธืื ืึท ืงื ืืื
ืืืขืจ ืืขืจืคืืจ ืืื ืืขื ืืขืืืื ืืืืกืืืืื ืฆืืืื ืคืจืืืืขืืขื. ืขืจืฉืืขืจ, ืืื ืงืืงื ืื I/O ืืึทืกืข ืึทื ืขืืง ืงืจืืืืฅ ืืืขื ืฉืจืืืื ืฆื WAL? ืืืึธืก ืกืืกืืขื ืจืืคื ืืขื ืขื ืืขื ืืฆื? ืืืึธืก ืืื ืื ืืจืืืก ืคืื ืื ืจืขืงืึธืจืืก? ืฆืืืืืื ืก, ืืืื ืืืจ ืขื ืืคึฟืขืจื ืื ืคึฟืจืืื, ืืื ืืึธื ืืืจ ืจืขืคึผืจืึธืืืฆืืจื ืึท ืขื ืืขื ืืืขืจืงืืึธืื ืืื ืคืืึธ? ืื ืืืืกื ื ืืฉื ืคืึทืจืืขืกื ืึทื ืคืืึธ ืืื ืึท ืืืืขืจ ืคืืขืงืกืึทืืึทื ืืขืฆืืึทื ืืื ืคืืืข ืึธืคึผืฆืืขืก. ืืืจ ืกืึทืืืื ืืืืืข ืคึผืจืึธืืืขืืก ืืื ืืืื ืฆืืืึทื ื - ื ืืฆื ืื ืงืึทืืึทื ืื
ืืืจ ืขืจืฉืืขืจ ืืขืืืืื ื ืกืืจืึทืกืข ืฆื ืืืกืคืึธืจืฉื ืื ืขืืง ืกืขืจืืืขืจ ืคึฟืึทืจ Kubernetes ืืืขื ืขืก ืืื ืงืืื ืืึทืกืข ืืืืฃ ืืขื ืงื ืืื. ืืืจ ืืขืืขื ืึทื ืึผืืขื ืึทืืข WAL ืจืขืงืึธืจืืก ืืขื ืขื ืืืขืื ืื ืืขืืืข ืืจืืืก: 2200-2400 ืืืืขืก. ืืขืจืืืขืจ, ืืื ืื ืืึทืคึฟืขื ืืื ืื ืึธื ืืืื ืคืื ืืขื ืคึผืึธืกืื, ืืืจ ืกืคึผืขืฆืืคืืฆืืจื ืืขื ืคึผืึทืจืึทืืขืืขืจ -bs=2300 (bs ืืืื ืื ืืจืืืก ืืื ืืืืขืก ืคึฟืึทืจ ืืขืืขืจ ืคืืึธ ืคึผืึธืืืฆืืข). ืืึทืืขืจืงืื ื ืึทื ืื ืืจืืืก ืคืื ืื ืขืืง ืคึผืึธืืืฆืืข ืืขืคึผืขื ืืก ืืืืฃ ืื ืขืืง ืืืขืจืกืืข, ืคืึทืจืฉืคึผืจืืืืื ื, ืคึผืึทืจืึทืืขืืขืจ ืืืึทืืืขืก, ืืื"ื ื, ืืื ืึทืคืขืงืฅ ืื Fdatasync ืืขืืืืขืจ. ืืืื ืืืจ ืืึธืื ืึท ืขื ืืขื ืกืฆืขื ืึทืจ, ืื ืืขืจืืืื ืืืื ืขืืง ืคึผืจืึทืกืขืกืึทื ืืื ืกืืจืึทืกืข ืฆื ืืขืคึฟืื ืขื ืื ืคึผืื ืืืขื ื ืืืขืจื.
ืืขืจื ืึธื, ืฆื ืืึทืงืืืขื ืึท ืืืืข ืืขืืึทื ืง ืคืื ืืืึธืก ืื ืขืืง ืืขืงืข ืกืืกืืขื ืืื ืืื, ืืืจ ืกืืึทืจืืขื ืขืก ืืื ืกืืจืึทืกืข ืืื ืื -ffttT ืึธืคึผืฆืืขืก. ืึทืืื ืืืจ ืืขืคืจืืืื ืฆื ืื ืืขืจืืืื ืื ืงืื ื ืคึผืจืึทืกืขืกืึทื ืืื ืจืขืงืึธืจืืืจื ืื ืจืขืืืืืึทื ืคืื ืืขืืขืจ ืคืื ืืื ืืื ืึท ืืึทืืื ืืขืจ ืืขืงืข, ืืื ืืืื ืืึทืงืืืขื ืืืืืืื ืจืืคึผืึธืจืฅ ืืืขืื ืื ืึธื ืืืื ืืื ืืขืืืืขืจ ืคืื ืืขืืขืจ ืกืืกืืขื ืจืืคื. ืืืจ ืืขืืืืื ื lsof ืฆื ืืึทืฉืืขืืืงื ืืื ืืืขืจ ืึทื ืึทืืืกืืก ืคืื ืื ืกืืจืึทืกืข ืจืขืืืืืึทื ืืื ืืขื ืืืึธืก ืืขืงืข ืืืกืงืจืืคึผืืึธืจ ืืื ืืขื ืืฆื ืคึฟืึทืจ ืืืึธืก ืฆืื. ืึทืืื ืืื ืื ืืืืฃ ืคืื ืกืืจืึทืกืข, ืื ืจืขืืืืืึทืื ืืขืืืืื ืืืืื ืืขื ืขื ืืืงืืืขื. ืกืื ืืงืจืึทื ืึทืืืืฉืึทื ืฆืืื ืกืืึทืืืกืืืง ืืืฉืืขืืืงื ืึทื wal_fsync_duration_seconds ืคึฟืื ืขืืง ืืื ืงืึธื ืกืืกืืขื ื ืืื fdatasync ืงืึทืืืก ืืื WAL ืืขืงืข ืืืกืงืจืืคึผืืึธืจืก.
ืืืจ ืืืจืืืขืืื ืืขื ืื ืืึทืงืืืืขื ืืืืฉืึทื ืคึฟืึทืจ ืคืืึธ ืืื ืืืืกืืขืจืืืืืื ืึธืคึผืฆืืขืก ืคึฟืึทืจ ืืื ืืืขืจ ืฉืจืืคื ืึทืืื ืึทื ืคืืึธ ืืืึธืื ืืืฉืขื ืขืจืืื ืึท ืืึทืกืข ืขื ืืขื ืฆื ืขืืง. ืืืจ ืืืื ืึธืคึผืืขืฉืืขืื ืกืืกืืขื ืงืึทืืืก ืืื ืืืืขืจ ืืขืืืืขืจ ืืืจื ืืืืคื ืคืืึธ ืคึฟืื ืกืืจืึทืกืข, ืขื ืืขื ืฆื ืขืืง.
ืืืจ ืืึธืื ืงืขืจืคืึทืื ืืืืกืืขืจืืืืืื ืื ืืืขืจื ืคืื ืื - ืืจืืืก ืคึผืึทืจืึทืืขืืขืจ ืฆื ืคืึธืจืฉืืขืื ืื ืืื ืฆืข ื / ืึธ ืืึทืกืข ืคืื โโืคืืึธ. ืืื ืืื ืืืขืจ ืคืึทื, ืืึธืก ืืื ืื ืืึทื ืฅ ื ืืืขืจ ืคืื ืืืืขืก ืืขืฉืจืืื ืฆื ืื ืกืืึธืจืืืืฉ. ืขืก ืืื ืืขืืืขื ืืืืึทื ืคึผืจืึทืคึผืึธืจืฉืึทื ืึทื ืฆื ืื ื ืืืขืจ ืคืื ืฉืจืืึทืื (ืืื ืคืืึทืืึทืกืื ืง) ืกืืกืืขื ืจืืคื. ืคึฟืึทืจ ืึท ืืืืขืจ ืืืขืจื ืคืื bs, ืื ื ืืืขืจ ืคืื fdatasync ืจืืคื = ืืจืืืก / ืืก. ืืืืืืื ืืืจ ืืืื ืืื ืคืืจืืื ืืขืจืขืกืืจื ืืื ืืขื ืคืจืืฆืขื ืืื, ืืืื ืืืจ ืืขืืืื ืืืื ืืขื ืื ืืืกืืขืจื ืฆื ืืืื ืืืืขืจ, ืืื ืืืจ ืืืื ืืืืกืืขืจืขืื ื ืื 10^4 ืืืืื ืืื ื ืืขื ืื ืืขืืืขื (ืืืก ืืื 22 ืืืืืืก). ืืืื - ืืจืืืก ืืื ืงืืขื ืขืจืขืจ, โโืึทืืืืืืขืจื ืงืขื ืคึผืึทืกืืจื (ืืืฉื, ืขืืืขืืข ืคืืึทืืึทืกืื ืง ืงืึทืืืก ื ืขืืขื ืืขืจ ืืื ืืขืืืืื ืืืขื ืืื ืืืืจืงื ืื 99 ืคึผืขืจืกืขื ืืื).
ืคืจืืืืจื ืืึธืก ืืื
ืืืจ ืืขืืืืื ืืืจ ืืื ืฆื ื ืืฆื ืคืืึธ ืืื ืืขื ืืืื ืื ืกืืึธืจืืืืฉ ืืื ืฉื ืขื ืืขื ืื ืคึฟืึทืจ ืขืืง ืฆื ืืืจืืคืืจื ืืื. ืืืฆื ืืืจ ืงืขื ืขื ืคึผืจืืืืจื ืขืก ืคึฟืึทืจ ืืื ื ืืฆื, ืืืฉื, ืืืืจืืืึทื ืืืฉืื ืขื ืืื SSD ืกืืึธืจืืืืฉ ืืื
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