Every once in a while, we need to apply mass upgrades to our servers for various security and other upgrades.
Owner: Fedora Infrastructure Team
Contact: #fedora-admin, sysadmin-main, email@example.com, #fedora-noc
Location: All over the world.
Purpose: Apply kernel/other upgrades to all of our servers
- Follow the Outage Infrastructure SOP and send advance notification to fedora-infrastructure-list and fedora-devel-announce. Try to schedule the update at a time when many admins are around to help/watch for problems.
- Plan an order for rebooting the machines considering two factors:
- Location of systems on the kvm or xen hosts. [You will normally reboot all systems on a host together]
- Impact of systems going down on other services, operations and users. Thus since the database servers and nfs servers are the backbone of many other systems, they and systems that are on the same xen boxes would be rebooted before other boxes.
- To aid in organizing a mass upgrade/reboot with many people helping, it may help to create a checklist of machines in a gobby document.
- Switch DNS to point to PHX only in advance. This allows the external proxy servers to be rebooted without causing downtime.
- Schedule downtime in nagios
- Make doubly sure that various app owners are aware of the reboots
Any updates that can be tested in staging or a pre-production environment should be tested there first. Including new kernels, updates to core database applications / libraries. Web applications, libraries, etc.
While this may not be a complete list, here are some special things that must be taken into account before rebooting certain systems:
Before the following machines are rebooted, all koji builders should be disabled and all running jobs allowed to complete:
The following machines need services to be shutdown manually before they are rebooted:
- noc1 (tell zodbot to quit first)
The following machines require post-boot actions (mostly entering passphrases). Make sure admins that have the passphrases are on hand for the reboot:
- app1 (Transifex SSH passphrase post-boot, see the Translations Infrastructure SOP)
- backup2 (LUKS passphrase on boot)
- sign-vault1 (NSS passphrase for sigul service)
- sign-bridge1 (NSS passphrase for sigul bridge service)
- noc1 (start zodbot, see the Zodbot Infrastructure SOP)
To minimize downtime as much as possible, the following main servers (and thus their respective xen hosts) should probably be rebooted first. Note that the xen servers may change from update to update.
- proxy2 (the proxy server for all PHX machines)
- fas1 (minor, only absolutely needed for certificate generation)
When rebooting servers, try to avoid having all of the machines in any of these groups down at the same time.
- proxy1, proxy2
- app1, app2, app3, app4
- fas1, fas2
- memcached1, memcached2,
- bastion1, bastion2 (these use heartbeat, but they will probably cause VPN blips on rebooting)
- koji1, koji2 (also on heartbeat)
- ns1, ns2
External xen hosts can generally be done at any time during this, with the exception of the main machines listed above.
Doing the upgrade
If possible, system upgrades should be done in advance of the reboot (with relevant testing of new packages on staging). To do the upgrades, make sure that the Infrastructure RHEL repo is updated as necessary to pull in the new packages (Infrastructure Yum Repo SOP)
On puppet1, as root run:
func-yum [--host=hostname] update
--host can be specified multiple times and takes wildcards.
pinging people as necessary if you are unsure about any packages:
Doing the reboot
In the order determined above, reboots will usually be grouped by the virtualization hosts that the servers are on. You can see the guests per virt host on puppet1 in /var/log/virthost-lists.out
For each host you will want to:
- connect and verify no one is logged in and using it. If they are contact them to log off, etc
- grep default /etc/grub.conf # make sure that the kernel you upgraded to will be the one rebooted.
- shutdown -h now
This is also a good time to double check that each guest you are starting up is set to be restarted on reboot of the virt host.
- Make sure that everything's running fine
- Reenable nagios notification as needed
- Make sure to perform any manual post-boot setup (such as loading SSH keys for transifex or entering passphrases for encrypted volumes)