Is your Elasticsearch "Trimmed"? | Elastic Blog
엔지니어링

Elasticsearch에 Trim이 되어 있나요?

Elasticsearch Trim ?

Elastic Elasticsearch , . .

recurring-elasticsearch-slowness

2016 9 26 2016 10 3 , 2016 10 10 . ?

2016 9 26
2016 10 3
2016 10 10

, . Ubuntu 16.04 RAID-0 SSD 2 .

Ubuntu Server 16.04 LTS VM cron.weekly . fstrim .

vagrant@ubuntu1604vbox:/etc/cron.weekly$ ls
fstrim  man-db

TRIM ?

Wikipedia :

trim (ATA TRIM, SCSI UNMAP) (SSD) .

SSD (NAND) . 3 SSD .

  1. . .
  2. / .
  3. , SSD !

(Garbage Collection) , . SSD OS IO , (Write amplification) .

OS . GC SSD . OS TRIM SSD . .

  • GC (OS )
  • GC

?

SSD SSD . Ubuntu fstrim crontab .

?

! 2016 10 17 fstrim cronjob .

elasticsearch-performance-after-trim

TRIM (PMC) 10 . TRIM .

ten-rally-benchmark-iterations-notrim

CentOS-7 fstrim.service systemd timer . .

LVM issue_discards /etc/lvm/lvm.conf 1 . dm-crypt Linux . lvm/dm-crypt TRIM ArchLinux wiki .

TRIM SSD . Amazon Instance Store-Backed Linux AMI .

Elasticsearch IO . SSD , TRIM , TRIM . !