---
id: 5e266165-1f58-48f5-acf5-26dae4567819
---

# Postgres Connection Limit Reached
---

This incident type occurs when the maximum number of connections allowed to a Postgres database has been reached. This prevents new connections from being established and can result in errors or downtime. It is important to monitor connection usage and adjust the maximum connection limit as needed to prevent this issue from occurring.

### Parameters
```shell
export VERSION="PLACEHOLDER"

export DATABASE_NAME="PLACEHOLDER"

export DESIRED_MAXIMUM_CONNECTIONS="PLACEHOLDER"
```

## Debug

### Check current Postgres connections
```shell
sudo su - postgres -c "psql -c 'select count(*) from pg_stat_activity;'"
```

### Check Postgres configuration file for connection settings
```shell
sudo cat /etc/postgresql/${VERSION}/main/postgresql.conf | grep 'max_connections'
```

### Check logs for any connection errors
```shell
sudo tail -n 100 /var/log/postgresql/postgresql-${VERSION}-main.log | grep -i 'connection'
```

### Check Postgres connection limit
```shell
sudo su - postgres -c "psql -c 'show max_connections;'"
```

### Check for any idle connections and terminate them
```shell
sudo su - postgres -c "psql -c 'SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = ${DATABASE_NAME} AND pid <> pg_backend_pid();'"
```

## Repair

### Increase the maximum number of connections allowed by the Postgres database. This can be done in the postgresql.conf file by modifying the max_connections parameter.
```shell


#!/bin/bash



# Set the maximum number of connections desired

MAX_CONNECTIONS=${DESIRED_MAXIMUM_CONNECTIONS}



# Modify the postgresql.conf file to set the new maximum connections

sed -i "s/^max_connections = .*$/max_connections = ${MAX_CONNECTIONS}/" /etc/postgresql/${VERSION}/main/postgresql.conf



# Restart the Postgres service to apply the changes

systemctl restart postgresql.service


```

This incident type occurs when the maximum number of connections allowed to a Postgres database has been reached. This prevents new connections from being established and can result in errors or downtime. It is important to monitor connection usage and adjust the maximum connection limit as needed to prevent this issue from occurring.


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Tomcat High JDBC Connection Pool Usage Incident.

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Redis Rejected Connections Incident

This incident type occurs when there are too many locks acquired on a Postgresql database instance. This can cause issues with database performance and functionality. It may be necessary to adjust the max\_locks\_per\_transaction setting in Postgresql to prevent this issue from occurring.


Postgresql too many locks acquired

This incident type refers to a situation where the Postgresql database has a high rollback rate, which means that a high percentage of transactions are being aborted compared to the committed ones. This can cause issues with data consistency and performance, and may require investigation and resolution by the responsible team. The incident details may include information about the affected database instance, the service or system impacted, the urgency level, and any related alerts or escalations.


Postgresql high rollback rate incident

```shell
export VERSION="PLACEHOLDER"

export DATABASE_NAME="PLACEHOLDER"

export DESIRED_MAXIMUM_CONNECTIONS="PLACEHOLDER"
```


### Check current Postgres connections

```shell
sudo su - postgres -c "psql -c 'select count(*) from pg_stat_activity;'"
```

### Check Postgres configuration file for connection settings

```shell
sudo cat /etc/postgresql/${VERSION}/main/postgresql.conf | grep 'max_connections'
```

### Check logs for any connection errors

```shell
sudo tail -n 100 /var/log/postgresql/postgresql-${VERSION}-main.log | grep -i 'connection'
```

### Check Postgres connection limit

```shell
sudo su - postgres -c "psql -c 'show max_connections;'"
```

### Check for any idle connections and terminate them

```shell
sudo su - postgres -c "psql -c 'SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = ${DATABASE_NAME} AND pid <> pg_backend_pid();'"
```


### Increase the maximum number of connections allowed by the Postgres database. This can be done in the postgresql.conf file by modifying the max\_connections parameter.

```shell


#!/bin/bash



# Set the maximum number of connections desired

MAX_CONNECTIONS=${DESIRED_MAXIMUM_CONNECTIONS}



# Modify the postgresql.conf file to set the new maximum connections

sed -i "s/^max_connections = .*$/max_connections = ${MAX_CONNECTIONS}/" /etc/postgresql/${VERSION}/main/postgresql.conf



# Restart the Postgres service to apply the changes

systemctl restart postgresql.service


```


Postgres Connection Limit Reached

Overview

Parameters

Debug

Check current Postgres connections

Check Postgres configuration file for connection settings

Check logs for any connection errors

Check Postgres connection limit

Check for any idle connections and terminate them

Repair

Increase the maximum number of connections allowed by the Postgres database. This can be done in the postgresql.conf file by modifying the max_connections parameter.

Learn more

Related Runbooks

Tomcat High JDBC Connection Pool Usage Incident.

Tomcat Connection Pool Exhaustion Incident

Redis Rejected Connections Incident

Postgresql too many locks acquired

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