---
name: "pcp_node_info"
section: "1"
platform: "linux"
package: "pgpool2"
version: "4.6.1-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/pcp_node_info"
---

# pcp\_node\_info(1)

displays the information on the given node ID

## NAME

pcp\_node\_info - displays the information on the given node ID

## SYNOPSIS

**pcp\_node\_info** \[*option*...\] \[*node\_id*\]

## DESCRIPTION

**pcp\_node\_info** displays the information on the given node ID.

## OPTIONS

- **-n** *node\_id* **--node-id=***node\_id*

  The index of backend node to get information of.

- **-a** **--all**

  Display all backend nodes information.

**Other options**

See [**pcp\_common\_options**(1)](/pcp_common_options/1.md).

## EXAMPLE

Here is an example output:

```
$ pcp_node_info -w -p 11001 -n 1
/tmp 11003 1 0.500000 waiting up standby standby 0 streaming async 2021-02-27 14:51:30
```

The result is in the following order:

```
1. hostname
2. port number
3. status
4. load balance weight
5. status name
6. actual backend status (obtained using PQpingParams. Pgpool-II 4.3 or later)
7. backend role
8. actual backend role (obtained using pg_is_in_recovery. Pgpool-II 4.3 or later)
9. replication delay
10. replication state (taken from pg_stat_replication. Pgpool-II 4.1 or later)
11. sync replication state (taken from pg_stat_replication. Pgpool-II 4.1 or later)
12. last status change time
```

3 (status) is represented by a digit from \[0 to 3\].

• 0 - This state is only used during the initialization. PCP will never display it.

• 1 - Node is up. No connections yet.

• 2 - Node is up. Connections are pooled.

• 3 - Node is down.

4 (load balance weight) is displayed in normalized format (0 - 1).

6 shows the backend status in real time. The info is obtained by calling **PQpingParams** at the time when the command is invoked. **PQpingParams** is only available in PostgreSQL 9.1 or later. If Pgpool-II was built with PostgreSQL 9.0 or earlier, the column shows "unknown". Also if health check is disabled, it shows "unknown". When a backend node is detached by [**pcp\_detach\_node**(1)](/pcp_detach_node/1.md), the status managed by Pgpool-II will be "down", while the actual backend status is "up". Thus it is possible that 5 does not match with 6. However it should not happen that 5 is "up" while 6 is "down".

8 shows the backend status in real time. The result will be either "primary" or "standby", and possibly "unknown" if information retrieval failed. Since Pgpool-II searches backend nodes in the node id order and assumes the last found node is primary, it is possible that 7 does not match 8 when there are multiple nodes that are not standby by erroneous operations (this command is useful to find such that situation). In other than streaming replication mode, the status will be either "main" or "replica". Unlike streaming replication mode **pg\_is\_in\_recovery** is not called and value for 7 and 8 will be always the same.

To correctly 9, 10, 11 are displayed, sr\_check\_period must not be 0. 10, 11 will not be displayed if sr\_check\_user is not PostgreSQL super user nor it's not in "pg\_monitor" group.

**Note**\

To make sr\_check\_user in pg\_monitor group, execute following SQL command by PostgreSQL super user (replace "sr\_check\_user" with the setting of sr\_check\_user):

```
GRANT pg_monitor TO sr_check_user;
```

For PostgreSQL 9.6, there's no pg\_monitor group and sr\_check\_user must be PostgreSQL super user.

From Pgpool-II 4.4, 9 (replication delay) is displayed in either bytes or seconds. See delay\_threshold\_by\_time for more details.

The **-a** or **--all** option lists all backend nodes information.

```
$ pcp_node_info -w -p 11001 -a
/tmp 11002 1 0.500000 waiting up primary primary 0 none none 2021-02-27 14:51:30
/tmp 11003 1 0.500000 waiting up standby standby 0 streaming async 2021-02-27 14:51:30
```

The **--verbose** option can help understand the output. For example:

```
$ pcp_node_info -w -p 11001 --verbose 1
Hostname               : /tmp
Port                   : 11003
Status                 : 1
Weight                 : 0.500000
Status Name            : waiting
Backend Status Name    : up
Role                   : standby
Backend Role           : standby
Replication Delay      : 0
Replication State      : streaming
Replication Sync State : async
Last Status Change     : 2021-02-27 14:51:30
```