opendev/system-config
Code Issues Proposed changes

Add afsdb03 openstack.org

Browse Source 
We are in the process of upgrading the AFS servers to focal.  As
explained by auristor (extracted from IRC below) we need 3 servers to
actually perform HA with the ubik protocol:

 the ubik quorum is defined by the list of voting primary ip addresses
 as specified in the ubik service's CellServDB file.  The server with
 the lowest ip address gets 1.5 votes and the others 1 vote.  To win
 election requires greater than 50% of the votes.  In a two server
 configuration there are a total of 2.5 votes to cast.  1.5 > 2.5/2 so
 afsdb02.openstack.org always wins regardless of what
 afsdb01.openstack.org says.  And afsb01.openstack.org can never win
 because 1 < 2.5/2.  by adding a third ubik server to the quorum, the
 total votes cast are 3.5 and it always requires the vote of two
 servers to elect a winner ...  if afsdb03 is added with the highest
 ip address, then either afsdb01 or afsdb02 can be elected

Add a third server which is a focal host and related configuration.

Change-Id: I59e562dd56d6cbabd2560e4205b3bd36045d48c2
This commit is contained in:
Ian Wienand 2021-03-01 15:51:49 +11:00
parent b150237db0
commit 3f1d67b99f
5 changed files with 21 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
doc/source/afs.rst
View File

@ -23,6 +23,7 @@ At a Glance
:Hosts:
* afsdb01.openstack.org (a vldb and pts server in DFW)
* afsdb02.openstack.org (a vldb and pts server in ORD)
* afsdb03.openstack.org (a second vldb and pts server in DFW)
* afs01.dfw.openstack.org (a fileserver in DFW)
* afs02.dfw.openstack.org (a second fileserver in DFW)
* afs01.ord.openstack.org (a fileserver in ORD)
@ -58,8 +59,11 @@ Our implementation follows the common recommendation to colocate the
VLDB and PTS servers, and so they both run on our afsdb* servers.
These servers all have the same information and communicate with each
other to keep in sync and automatically provide high-availability
service. For that reason, one of our DB servers is in the DFW region,
and the other in ORD.
service. As described in
`<https://docs.openafs.org/AdminGuide/HDRWQ101.html>`__ the Ubik
protocol requires three servers to maintain availability; for that
reason, two of our DB servers are in the DFW region, and the other in
ORD.
Fileservers contain volumes, each of which is a portion of the file
space provided by that cell. A volume appears as at least one
@ -614,7 +618,7 @@ afsdb0X.openstack.org
~~~~~~~~~~~~~~~~~~~~~
We have redundant AFS DB servers. You can take one down without causing
a service outage as long as the other remains up. To do this safely::
a service outage as long as the others remain up. To do this safely::
root@afsdb01:~# bos shutdown afsdb01.openstack.org -wait -localauth
root@afsdb01:~# bos status afsdb01.openstack.org -localauth
@ -633,7 +637,7 @@ Finally check that the service is back up and running::
Instance ptserver, currently running normally.
Instance vlserver, currently running normally.
Now you can repeat the process against afsdb02.
Now you can repeat the process against afsdb02 or afsdb03.
afs0X.openstack.org
~~~~~~~~~~~~~~~~~~~
@ -683,12 +687,14 @@ Perform maintenance, then restart as above and check the status again::
DNS Entries
-----------
AFS uses the following DNS entries::
AFS uses the following DNS entries which indicate an even balance::
_afs3-prserver._udp.openstack.org. 300 IN SRV 10 10 7002 afsdb01.openstack.org.
_afs3-prserver._udp.openstack.org. 300 IN SRV 10 10 7002 afsdb02.openstack.org.
_afs3-prserver._udp.openstack.org. 300 IN SRV 10 10 7002 afsdb03.openstack.org.
_afs3-vlserver._udp.openstack.org. 300 IN SRV 10 10 7003 afsdb01.openstack.org.
_afs3-vlserver._udp.openstack.org. 300 IN SRV 10 10 7003 afsdb02.openstack.org.
_afs3-vlserver._udp.openstack.org. 300 IN SRV 10 10 7003 afsdb03.openstack.org.
Be sure to update them if volume location and PTS servers change. Also note
that only A (IPv4 address) records are used in the SRV data. Since OpenAFS

1
hiera/common.yaml
View File

@ -206,6 +206,7 @@ cacti_hosts:
- afs01.ord.openstack.org
- afsdb01.openstack.org
- afsdb02.openstack.org
- afsdb03.openstack.org
- apps.openstack.org
- ask.openstack.org
- backup01.ord.rax.opendev.org

7
inventory/base/hosts.yaml
View File

@ -42,6 +42,13 @@ all:
region_name: ORD
public_v4: 23.253.200.228
public_v6: 2001:4801:7824:104:805d:9ae0:cb8d:3a86
afsdb03.openstack.org:
ansible_host: 104.130.158.72
location:
cloud: openstackci-rax
region_name: DFW
public_v4: 104.130.158.72
public_v6: 2001:4800:7818:104:be76:4eff:fe04:2952
ask01.openstack.org:
ansible_host: 104.239.149.165
location:

1
playbooks/roles/openafs-server-config/files/CellServDB
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@ -1,3 +1,4 @@
>openstack.org #Cell name
104.130.136.20 #afsdb01.openstack.org
23.253.200.228 #afsdb02.openstack.org
104.130.158.72 #afsdb03.openstack.org

1
roles/openafs-client/templates/CellServDB
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@ -1,6 +1,7 @@
>openstack.org #OpenStack
104.130.136.20 #afsdb01.openstack.org
23.253.200.228 #afsdb02.openstack.org
104.130.158.72 #afsdb03.openstack.org
>grand.central.org #GCO Public CellServDB 28 Jan 2013
18.9.48.14 #grand.mit.edu
128.2.203.61 #penn.central.org