```bash
$ sudo cp init.debian /etc/init.d/slony_failover
-$ cp slony_failover.conf /var/slony/failover/slony_failover.conf
+$ cp slony_failover.conf /var/slony/slony_failover/slony_failover.conf
$ sudo chmod +x /etc/init.d/slony_failover
$ sudo update-rc.d slony_failover start 99 2 3 4 5 . stop 24 0 1 6
$ sudo invoke-rc.d slony_failover start
##Command line parameters
```bash
-$ ./failover.pl [options]
+$ ./slony_failover.pl [options]
```
|Switch | Description
| General |**separate_working_directory** | boolean | *'true'* | Append a separate working directory to the prefix_directory for each run
| General |**slonik_path** | /full/path/to/bin/directory | *null* | Slonik binary if not in current path
| General |**pid_filename** | /path/to/pidfile | *'/var/run/slony_failover.pid'* | Pid file to use when running in autofailover mode
-| General |**enable_try_blocks** | boolean | *false* | Write slonik script with try blocks where possible to aid error handling
+| General |**enable_try_blocks** | boolean | *false* | Write slonik script with try blocks where possible to aid error handling
| General |**lockset_method** | single/multiple | *'multiple'* | Write slonik script that locks all sets
-| General |**pull_aliases_from_comments** | boolean | *false* | If true, script will pull text from between parentheses in comments fields
-| | | | | and use to generate (possibly) meaningful aliases for nodes and sets.
+| General |**pull_aliases_from_comments** | boolean | *false* | If true, script will pull text from comment fields and use to generate
+| | | | | possibly meaningful aliases for nodes and sets.
+| | | | | For sl_set this uses the entire comment, and sl_node text in parentheses.
| General |**log_line_prefix** | text | *null* | Prefix to add to log lines, special values:
| | | | | %p = process ID
| | | | | %t = timestamp without milliseconds
| Autofailover|**autofailover_forwarding_providers** | boolean | *'false'* | If true a failure of a pure forwarding provider will also trigger failover
| Autofailover|**autofailover_config_any_node** | boolean | *'true'* | After reading the initial cluster configuration, subsequent reads of the configuration
| | | | | will use conninfo read from sl_subscribe to read from any node.
-| Autofailover|**autofailover_poll_interval** | integer | 500 | How often to check for failure of nodes (milliseconds)
-| Autofailover|**autofailover_node_retry** | integer | 2 | When failure is detected, retry this many times before initiating failover
-| Autofailover|**autofailover_sleep_time** | integer | 1000 | Interval between retries (milliseconds)
+| Autofailover|**autofailover_poll_interval** | integer | *500* | How often to check for failure of nodes (milliseconds)
+| Autofailover|**autofailover_node_retry** | integer | *2* | When failure is detected, retry this many times before initiating failover
+| Autofailover|**autofailover_sleep_time** | integer | *1000* | Interval between retries (milliseconds)
+| Autofailover|**autofailover_perspective_sleep_time** | integer | *20000* | Interval between lag reads for failed nodes from surviving nodes. If greater
+ | than zero any observation that nodes have failed is checked from surviving nodes
+ | perspective by checking if lag times are extending. This does not guarantee 100%
+ | the nodes are down but if set to a large enough interval can back up our observation.
+| Autofailover|**autofailover_majority_only** | boolean | *false* | Only fail over if the quantity of surviving nodes is greater than the quantity of
+ | failed nodes. Intended to be used to prevent a split-brain scenario in
+ | conjunction with some other logic to monitor and fence off the old origin if it
+ | is in the minority.
+| Autofailover|**autofailover_is_quorum** | boolean | *false* | If this script is running on a separate host set to true to treat it as a quorum
+ | server. Effectively increments sum of surviving nodes when calculating the
+ | majority above.
Changes
-------
* 04/11/2012 - Experiment with different use of try blocks (currently can't use multiple lock sets indide try)
* 13/04/2014 - Update to work differently for Slony 2.2+
* 05/05/2014 - Experiment with autofailover ideas
+* 10/09/2014 - Add some logic to autofailover for doing extra checks from perspective of other nodes. Still a naive autofailover implementaition imho.
Licence
-------
projects / slony-i / slony_failover / blobdiff