The new field `compression` in the `cluster{}` block allows to
specify which compression mode to use between servers.
It can be simply specified as a boolean or a string for the
simple modes, or as an object for the "s2_auto" mode where
a list of RTT thresholds can be specified.
By default, if no compression field is specified, the server
will use the s2_auto mode with default RTT thresholds of
10ms, 50ms and 100ms for the "uncompressed", "fast", "better"
and "best" modes.
```
cluster {
..
# Possible values are "disabled", "off", "enabled", "on",
# "accept", "s2_fast", "s2_better", "s2_best" or "s2_auto"
compression: s2_fast
}
```
To specify a different list of thresholds for the s2_auto,
here is how it would look like:
```
cluster {
..
compression: {
mode: s2_auto
# This means that for RTT up to 5ms (included), then
# the compression level will be "uncompressed", then
# from 5ms+ to 15ms, the mode will switch to "s2_fast",
# then from 15ms+ to 50ms, the level will switch to
# "s2_better", and anything above 50ms will result
# in the "s2_best" compression mode.
rtt_thresholds: [5ms, 15ms, 50ms]
}
}
```
Note that the "accept" mode means that a server will accept
compression from a remote and switch to that same compression
mode, but will otherwise not initiate compression. That is,
if 2 servers are configured with "accept", then compression
will actually be "off". If one of the server had say s2_fast
then they would both use this mode.
If a server has compression mode set (other than "off") but
connects to an older server, there will be no compression between
those 2 routes.
Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
New configuration fields:
```
cluster {
...
pool_size: 5
accounts: ["A", "B"]
}
```
The configuration `pool_size` in the example above means that this
server will create 5 routes to a remote server, assuming that that
server has the same `pool_size` setting.
Accounts (which are not part of the `accounts[]` configuration)
are assigned a specific route in this pool, and this will be the
same route on all servers in the cluster.
Accounts that are defined in the `accounts` field will each have
a dedicated route connection. This will allow suppression of the
account name in some of the route protocols, reducing bytes transmitted
which may increase performance.
Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
