doc: added Server Mode description
@@ -3907,7 +3907,41 @@ Default config:
*Replication metrics* use information from `pg_replication_slots`.
-1. **Non-active Replication Slots**
+
+1. **Server Mode**
+
+ Zabbix item:
+ <table>
+ <tr>
+ <th>Name</th>
+ <td>PostgreSQL: server mode</td>
+ </tr>
+ <tr>
+ <th>Key</th>
+ <td>pgsql.server_mode</td>
+ </tr>
+ <tr>
+ <th>Type</th>
+ <td>Text</td>
+ </tr>
+ <tr>
+ <th>Units</th>
+ <td></td>
+ </tr>
+ <tr>
+ <th>Delta</th>
+ <td>As Is</td>
+ </tr>
+ <tr>
+ <th>Supported Version</th>
+ <td>9.5+</td>
+ </tr>
+ </table>
+
+ *Server Mode* shows server status as `MASTER` or `STANDBY`.
+
+
+2. **Non-active Replication Slots**
Zabbix item:
<table>
@@ -3940,7 +3974,7 @@ Default config:
*Non-active Replication Slots* calculates as count of slots with `false` active status.
-2. **Streaming Replication Lag**
+3. **Streaming Replication Lag**
Zabbix item:
<table>
@@ -4029,9 +4063,11 @@ Default config:
### Triggers
-1. **PostgreSQL number of non-active replication slots on {HOSTNAME} (value={ITEM.LASTVALUE})**
+1. **PostgreSQL server mode changed on {HOSTNAME} to {ITEM.LASTVALUE}**
+
+2. **PostgreSQL number of non-active replication slots on {HOSTNAME} (value={ITEM.LASTVALUE})**
-2. **PostgreSQL streaming lag too high on {HOSTNAME} (value={ITEM.LASTVALUE})**
+3. **PostgreSQL streaming lag too high on {HOSTNAME} (value={ITEM.LASTVALUE})**
Triggers if *PostgreSQL: streaming replication lag* exceeds `lag_more_than_in_sec`.
### Temp Files
