You are browsing a read-only backup copy of Wikitech. The live site can be found at

Portal:Data Services/Admin/Wiki Replicas

From Wikitech-static
< Portal:Data Services‎ | Admin
Revision as of 13:43, 15 November 2017 by imported>Arturo Borrero Gonzalez (→‎Storage layer: all 3 servers are the same)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

This page holds all the knowledge we have regarding Wiki Replicas for admins.

Service architecture by layers

Description of how the service is currently deployed.

Here is a general diagram of how things are:


Physical layer

This service is build on top of several physical servers:

  • labsdb1009.eqiad.wmnet
  • labsdb1010.eqiad.wmnet
  • labsdb1011.eqiad.wmnet

All servers are the same:

  • HP ProLiant DL380 Gen9
  • 16 CPU Intel(R) Xeon(R) CPU E5-2637 v3 @ 3.50GHz
  • 500GB RAM
  • 1 hard-disc in /dev/sda with 11.7 TiB (probaby RAID, using hpsa kernel driver)
  • 4 x 1GB ethernet interfaces (tg3)


  • isn't this information somewhere else?
  • no RAID status monitoring from userspace?

Storage layer

The service has a concrete storage configuration.

As seen by fdisk:

% sudo fdisk -l
Disk /dev/sda: 11.7 TiB, 12802299617280 bytes, 25004491440 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 262144 bytes / 2097152 bytes
Disklabel type: gpt
Disk identifier: 0933E022-348E-4F59-8F84-D4C3B32090BD

Device        Start         End     Sectors  Size Type
/dev/sda1      4096    78123007    78118912 37.3G Linux filesystem
/dev/sda2  78123008    93749247    15626240  7.5G Linux swap
/dev/sda3  93749248 25004490751 24910741504 11.6T Linux LVM

Disk /dev/mapper/tank-data: 11.6 TiB, 12754295455744 bytes, 24910733312 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 262144 bytes / 2097152 bytes

As seen by the LVM stack:

% sudo pvs
  PV         VG   Fmt  Attr PSize  PFree
  /dev/sda3  tank lvm2 a--  11.60t    0 
% sudo vgs
  VG   #PV #LV #SN Attr   VSize  VFree
  tank   1   1   0 wz--n- 11.60t    0 
% sudo lvs
  LV   VG   Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  data tank -wi-ao---- 11.60t  

As seen by df:

% df -h
Filesystem             Size  Used Avail Use% Mounted on
udev                   252G     0  252G   0% /dev
tmpfs                   51G  4.1G   47G   8% /run
/dev/sda1               37G   11G   25G  31% /
tmpfs                  252G     0  252G   0% /dev/shm
tmpfs                  5.0M     0  5.0M   0% /run/lock
tmpfs                  252G     0  252G   0% /sys/fs/cgroup
/dev/mapper/tank-data   12T  6.5T  5.2T  56% /srv

All 3 servers should have more or less the same storage configuration.

DB layer

The databases in this service have a concrete layout/configuration.

Higher layers

Such as applications running on top, proxys, caches, et al.

From production to wiki-replicas

Wiki databases from production are copied and sanitized to serve wiki-replicas.

Admin guide

Docs to perform common tasks related to this service. As detailed as possible.


Before this new cluster, we had an old cluster composed of physical servers: labsdb1001, labsdb1002 and labsdb1003. At the time of this writing, the last standing server is labsdb1003, which is going down in December 2017.

See also