github/repmgr
1
0
Fork 0
mirror of https://github.com/EnterpriseDB/repmgr.git synced 2026-03-24 15:46:29 +00:00
Code Issues Packages Projects Releases 1 Wiki Activity

cluster show: differentiate unreachable status

Browse Source 
Differentiate between unreachable nodes and nodes which are running
but rejecting connections.
This commit is contained in:
Ian Barwick
2019-02-15 15:55:36 +09:00
parent 9338a9e233
commit 3a5a4388c7
5 changed files with 109 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
doc/appendix-release-notes.sgml
View File

@@ -88,6 +88,18 @@ REPMGRD_OPTS="--daemonize=false"</programlisting>
</para>
</listitem>
<listitem>
<para>
<command><link linkend="repmgr-cluster-show">repmgr cluster show</link></command>:
differentiate between unreachable nodes and nodes which are running but rejecting connections.
</para>
<para>
This makes it possible to see whether a node is unreachable at network level,
or if it is running but rejecting connections for some reason.
</para>
</listitem>
<listitem>
<para>
Add <option>--dry-run</option> to <command><link linkend="repmgr-standby-promote">repmgr standby promote</link></command> (GitHub #522).

64
doc/repmgr-cluster-show.sgml
View File

@@ -22,6 +22,14 @@
directly and can be run on any node in the cluster; this is also useful when analyzing
connectivity from a particular node.
</para>
<para>
Node availability is tested by connecting from the node where
<command>repmgr cluster show</command> is executed, and does not necessarily imply the node
is down. See <xref linkend="repmgr-cluster-matrix"> and <xref linkend="repmgr-cluster-crosscheck"> to get
better overviews of connections between nodes.
</para>
</refsect1>
<refsect1>
@@ -55,30 +63,48 @@
<title>Notes</title>
<para>
The column <literal>Role</literal> shows the expected server role according to the
&repmgr; metadata. <literal>Status</literal> shows whether the server is running or unreachable.
&repmgr; metadata.
</para>
<para>
<literal>Status</literal> shows whether the server is running or unreachable.
If the node has an unexpected role not reflected in the &repmgr; metadata, e.g. a node was manually
promoted to primary, this will be highlighted with an exclamation mark, e.g.:
promoted to primary, this will be highlighted with an exclamation mark.
If a connection to the node cannot be made, this will be highlighted with a question mark.
Note that the node will only be shown as <literal>? unreachable</literal>
if a connection is not possible at network level; if the PostgreSQL instance on the
node is pingable but not accepting connections, it will be shown as <literal>? running</literal>.
</para>
<para>
In the following example, executed on <literal>node3</literal>, <literal>node1</literal> is not reachable
at network level and assumed to be down; <literal>node2</literal> has been promoted to primary
(but <literal>node3</literal> is not attached to it, and its metadata has not yet been updated);
<literal>node4</literal> is running but rejecting connections (from <literal>node3</literal> at least).
<programlisting>
$ repmgr -f /etc/repmgr.conf cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Connection string
----+-------+---------+----------------------+----------+----------+----------+-----------------------------------------
1 | node1 | primary | ? unreachable | | default | 100 | host=db_node1 dbname=repmgr user=repmgr
2 | node2 | standby | ! running as primary | node1 | default | 100 | host=db_node2 dbname=repmgr user=repmgr
3 | node3 | standby | running | node1 | default | 100 | host=db_node3 dbname=repmgr user=repmgr
4 | node4 | standby | ? running | node1 | default | 100 | host=db_node4 dbname=repmgr user=repmgr
ID | Name | Role | Status | Upstream | Location | Priority | Connection string
----+-------+---------+----------------------+----------+----------+----------+-----------------------------------------
1 | node1 | primary | ? unreachable | | default | 100 | host=db_node1 dbname=repmgr user=repmgr
2 | node2 | standby | ! running as primary | node1 | default | 100 | host=db_node2 dbname=repmgr user=repmgr
3 | node3 | standby | running | node1 | default | 100 | host=db_node3 dbname=repmgr user=repmgr
WARNING: following issues were detected
- unable to connect to node "node1" (ID: 1)
- node "node1" (ID: 1) is registered as an active primary but is unreachable
- node "node2" (ID: 2) is registered as standby but running as primary
WARNING: following issues were detected
- unable to connect to node "node1" (ID: 1)
- node "node1" (ID: 1) is registered as an active primary but is unreachable
- node "node2" (ID: 2) is registered as standby but running as primary
- unable to connect to node "node4" (ID: 4)
HINT: execute with --verbose option to see connection error messages</programlisting>
</para>
<para>
Node availability is tested by connecting from the node where
<command>repmgr cluster show</command> is executed, and does not necessarily imply the node
is down. See <xref linkend="repmgr-cluster-matrix"> and <xref linkend="repmgr-cluster-crosscheck"> to get
better overviews of connections between nodes.
</para>
<para>
To diagnose connection issues, execute <command>repmgr cluster show</command>
with the <option>--verbose</option> option; this will display the error message
for each failed connection attempt.
</para>
<tip>
<para>
Use <xref linkend="repmgr-cluster-matrix"> and <xref linkend="repmgr-cluster-crosscheck">
to diagnose connection issues across the whole replication cluster.
</para>
</tip>
</refsect1>
<refsect1>