mirror of https://github.com/status-im/consul.git
202 lines
8.3 KiB
Markdown
202 lines
8.3 KiB
Markdown
---
|
|
layout: "docs"
|
|
page_title: "Upgrading Specific Versions"
|
|
sidebar_current: "docs-upgrading-specific"
|
|
description: |-
|
|
Specific versions of Consul may have additional information about the upgrade process beyond the standard flow.
|
|
---
|
|
|
|
# Upgrading Specific Versions
|
|
|
|
The [upgrading page](/docs/upgrading.html) covers the details of doing
|
|
a standard upgrade. However, specific versions of Consul may have more
|
|
details provided for their upgrades as a result of new features or changed
|
|
behavior. This page is used to document those details separately from the
|
|
standard upgrade flow.
|
|
|
|
## Consul 0.6.4
|
|
|
|
Consul 0.6.4 made some substantial changes to how ACLs work with prepared
|
|
queries. Existing queries will execute with no changes, but there are important
|
|
differences to understand about how prepared queries are managed before you
|
|
upgrade. In particular, prepared queries with no `Name` defined will no longer
|
|
require any ACL to manage them, and prepared queries with a `Name` defined are
|
|
now governed by a new `query` ACL policy that will need to be configured
|
|
after the upgrade.
|
|
|
|
See the [Prepared Query ACLs](/docs/internals/acl.html#prepared_query_acls)
|
|
internals guide for more details about the new behavior and how it compares to
|
|
previous versions of Consul.
|
|
|
|
## Consul 0.6
|
|
|
|
Consul version 0.6 is a very large release with many enhancements and
|
|
optimizations. Changes to be aware of during an upgrade are categorized below.
|
|
|
|
#### Data store changes
|
|
|
|
Consul changed the format used to store data on the server nodes in version 0.5
|
|
(see 0.5.1 notes below for details). Previously, Consul would automatically
|
|
detect data directories using the old LMDB format, and convert them to the newer
|
|
BoltDB format. This automatic upgrade has been removed for Consul 0.6, and
|
|
instead a safeguard has been put in place which will prevent Consul from booting
|
|
if the old directory format is detected.
|
|
|
|
It is still possible to migrate from a 0.5.x version of Consul to 0.6+ using the
|
|
[consul-migrate](https://github.com/hashicorp/consul-migrate) CLI utility. This
|
|
is the same tool that was previously embedded into Consul. See the
|
|
[releases](https://github.com/hashicorp/consul-migrate/releases) page for
|
|
downloadable versions of the tool.
|
|
|
|
Also, in this release Consul switched from LMDB to a fully in-memory database for
|
|
the state store. Because LMDB is a disk-based backing store, it was able to store
|
|
more data than could fit in RAM in some cases (though this is not a recommended
|
|
configuration for Consul). If you have an extremely large data set that won't fit
|
|
into RAM, you may encounter issues upgrading to Consul 0.6.0 and later. Consul
|
|
should be provisioned with physical memory approximately 2X the data set size to
|
|
allow for bursty allocations and subsequent garbage collection.
|
|
|
|
#### ACL Enhancements
|
|
|
|
Consul 0.6 introduces enhancements to the ACL system which may require special
|
|
handling:
|
|
|
|
* Service ACLs are enforced during service discovery (REST + DNS)
|
|
|
|
Previously, service discovery was wide open, and any client could query
|
|
information about any service without providing a token. Consul now requires
|
|
read-level access at a minimum when ACLs are enabled to return service
|
|
information over the REST or DNS interfaces. If clients depend on an open
|
|
service discovery system, then the following should be added to all ACL tokens
|
|
which require it:
|
|
|
|
# Enable discovery of all services
|
|
service "" {
|
|
policy = "read"
|
|
}
|
|
|
|
Note that the agent's [`acl_token`](/docs/agent/options.html#acl_token) is used
|
|
when the DNS interface is queried, so be sure that token has sufficient
|
|
privileges to return the DNS records you expect to retrieve from it.
|
|
|
|
* Event and keyring ACLs
|
|
|
|
Similar to service discovery, the new event and keyring ACLs will block access
|
|
to these operations if the `acl_default_policy` is set to `deny`. If clients depend
|
|
on open access to these, then the following should be added to all ACL tokens which
|
|
require them:
|
|
|
|
event "" {
|
|
policy = "write"
|
|
}
|
|
|
|
keyring = "write"
|
|
|
|
Unfortunately, these are new ACLs for Consul 0.6, so they must be added after the
|
|
upgrade is complete.
|
|
|
|
#### Prepared Queries
|
|
|
|
Prepared queries introduce a new Raft log entry type that isn't supported on older
|
|
versions of Consul. It's important to not use the prepared query features of Consul
|
|
until all servers in a cluster have been upgraded to version 0.6.0.
|
|
|
|
#### Single Private IP Enforcement
|
|
|
|
Consul will refuse to start if there are multiple private IPs available, so
|
|
if this is the case you will need to configure Consul's advertise or bind addresses
|
|
before upgrading.
|
|
|
|
#### New Web UI File Layout
|
|
|
|
The release .zip file for Consul's web UI no longer contains a `dist` sub-folder;
|
|
everything has been moved up one level. If you have any automated scripts that
|
|
expect the old layout you may need to update them.
|
|
|
|
## Consul 0.5.1
|
|
|
|
Consul version 0.5.1 uses a different backend store for persisting the Raft
|
|
log. Because of this change, a data migration is necessary to move the log
|
|
entries out of LMDB and into the newer backend, BoltDB.
|
|
|
|
Consul version 0.5.1+ makes this transition seamless and easy. As a user, there
|
|
are no special steps you need to take. When Consul starts, it checks
|
|
for presence of the legacy LMDB data files, and migrates them automatically
|
|
if any are found. You will see a log emitted when Raft data is migrated, like
|
|
this:
|
|
|
|
```
|
|
==> Successfully migrated raft data in 5.839642ms
|
|
```
|
|
|
|
This automatic upgrade will only exist in Consul 0.5.1+ and it will
|
|
be removed starting with Consul 0.6.0+. It will still be possible to upgrade directly
|
|
from pre-0.5.1 versions by using the consul-migrate utility, which is available on the
|
|
[Consul Tools page](/downloads_tools.html).
|
|
|
|
## Consul 0.5
|
|
|
|
Consul version 0.5 adds two features that complicate the upgrade process:
|
|
|
|
* ACL system includes service discovery and registration
|
|
* Internal use of tombstones to fix behavior of blocking queries
|
|
in certain edge cases.
|
|
|
|
Users of the ACL system need to be aware that deploying Consul 0.5 will
|
|
cause service registration to be enforced. This means if an agent
|
|
attempts to register a service without proper privileges it will be denied.
|
|
If the `acl_default_policy` is "allow" then clients will continue to
|
|
work without an updated policy. If the policy is "deny", then all clients
|
|
will begin to have their registration rejected causing issues.
|
|
|
|
To avoid this situation, all the ACL policies should be updated to
|
|
add something like this:
|
|
|
|
# Enable all services to be registered
|
|
service "" {
|
|
policy = "write"
|
|
}
|
|
|
|
This will set the service policy to `write` level for all services.
|
|
The blank service name is the catch-all value. A more specific service
|
|
can also be specified:
|
|
|
|
# Enable only the API service to be registered
|
|
service "api" {
|
|
policy = "write"
|
|
}
|
|
|
|
The ACL policy can be updated while running 0.4, and enforcement will
|
|
being with the upgrade to 0.5. The policy updates will ensure the
|
|
availability of the cluster.
|
|
|
|
The second major change is the new internal command used for tombstones.
|
|
The details of the change are not important, however to function the leader
|
|
node will replicate a new command to its followers. Consul is designed
|
|
defensively, and when a command that is not recognized is received, the
|
|
server will panic. This is a purposeful design decision to avoid the possibility
|
|
of data loss, inconsistensies, or security issues caused by future incompatibility.
|
|
|
|
In practice, this means if a Consul 0.5 node is the leader, all of its
|
|
followers must also be running 0.5. There are a number of ways to do this
|
|
to ensure cluster availability:
|
|
|
|
* Add new 0.5 nodes, then remove the old servers. This will add the new
|
|
nodes as followers, and once the old servers are removed, one of the
|
|
0.5 nodes will become leader.
|
|
|
|
* Upgrade the followers first, then the leader last. Using `consul info`,
|
|
you can determine which nodes are followers. Do an in-place upgrade
|
|
on them first, and finally upgrade the leader last.
|
|
|
|
* Upgrade them in any order, but ensure all are done within 15 minutes.
|
|
Even if the leader is upgraded to 0.5 first, as long as all of the followers
|
|
are running 0.5 within 15 minutes there will be no issues.
|
|
|
|
Finally, even if any of the methods above are not possible or the process
|
|
fails for some reason, it is not fatal. The older version of the server
|
|
will simply panic and stop. At that point, you can upgrade to the new version
|
|
and restart the agent. There will be no data loss and the cluster will
|
|
resume operations.
|
|
|