Hybrid Cloud is an advanced concept, which has been evolved over the last few years. It is a very popular topology for any organization wanting to set up a foolproof Disaster Recovery Plan or to have redundancy on the systems. Once on having your hybrid cloud running, you have to know to keep track of what is happening to it all the time. Monitoring is an important aspect of maintaining your system to ensure that everything goes as planned and see if you need to change something. In database administration, there are various such things to keep a watch on. Some of these are specific to the database engine, providers, or the version you use. This article discusses what you need to monitor in PostgreSQL DB running on the hybrid cloud environment.
Things to monitor in PostgreSQL
While monitoring the database clusters or node, two major things needed to be taken into account:
- The operating system, and
- The database itself.
You have to custom define which of these metrics you may monitor from both sides and how you will be monitoring these. Also, you should keep in mind that when one of these metrics gets affected, it may also affect others and make the troubleshooting more complex and difficult to handle. Having a good monitoring and alerting system is crucial to make this task simpler and comfortable.
Another obvious thing you must note, which is common to most database engines and systems, is to monitor operating systems’ behavior. Let us see some crucial considerations to make here.
Excessive CPU usage may be a problem if it not a usual behavior and appropriate measures have been taken for the same. In such a case, it is crucial to identify the processes which are creating this issue. If you find a problem with the database processes, you have to check what is happening inside the database with excessive CPU usage.
RAM Memory / SWAP Usage
If you experience a high value for this metric and nothing changes in the system, you may probably have to check the DB configuration. Check for the parameters as work_mem and shared_buffers etc., which may affect it directly as these define the memory used for the PostgreSQL database to function.
Disk space usage
Any abnormal increase in disk space usage or consumption of disk access is needed to closely watch as there may be a high number of errors at the background logged on to the PostgreSQL log file. It may also be due to bad cache configuration, which may generate an important disk space consumption to process queries.
Load average is directly related to all three points we discussed above. A high load average may be resulting from excessive RAM, CPU, and disk usage.For better-managed services and remote database monitoring services, explore RemoteDBA.com.
Network issues may affect all systems as the applications may not connect to the DB with a network failure, so it is a crucial metric to be closely monitored. You may also monitor the latency and packet loss. Sometimes, the issue may be related to network saturation or maybe a hardware issue or bad network configuration.
Keep a watch on your PostgreSQL DB itself is so crucial to see if you have any issues. It is also important to know if you have to change anything to improve the database performance. The need for improvement is one important thing you have to keep on monitoring in a database. Let us see some of the crucial metrics to consider on database monitoring.
Databases are generally configured with stability and compatibility, so you have to know the queries and their structure to configure the DB based on your traffic nature. For PostgreSQL, you can use the ‘EXPLAIN’ command to keep a check on the query plan for specific queries. You can also check the volumes of SELECT, UPDATE, INSERT, or DELETEs queries coming on to each node. If a long query or many queries is running simultaneously, it could be a big problem for all your systems.
You should also watch the number of active sessions. If you are close to the limits, you have to consider anything wrong if you need to increment the max connection values by going to database configurations. The difference in this number can be the increase or decrease in the number of connections. Bad usage of locking, connection pooling, or network issues may be the most common issues related to the improper number of connections.
If there is a query waiting to run based on another query, then you have to check if that is a normal process or anything new. In many cases, if someone makes an update on the big table, this action may be adversely affecting the database’s usual behavior and thereby generate a lot of locks.
Status of replication
Some of the keys you need to monitor in terms of replication are the replication state and the lag. One of the most common issues related to it is networking issues, hardware resources, or dimensioning issues. If you face any replication issues, you may need to know it asap, and you may also need to fix it to ensure a high availability environment.
To avoid any data loss, you have to take proper data backups and know if the backup is properly completed and is fully usable if a situation arises. In normal cases, this is one of the last point admins consider, but this is one such important thing which may put you into deep trouble if a database failure occurs.
Along with these, some other important things to monitor for managing PostgreSQL in a hybrid environment are database logs, notifications, alerts, updates from time to time, etc. Monitoring is an absolute necessity no matter you run on cloud or on-premises.