Insight for DBAs

Percona Server for MongoDB 4.0 Is an Ideal Solution for Even More Production Use Cases

Percona Server for MongoDB Operator

Percona announces the planned release of Percona Server for MongoDB 4.0, the latest version of the company’s free, enhanced, drop-in replacement for MongoDB Community Edition. Percona Server for MongoDB 4.0 includes all the features of MongoDB Community Edition 4.0, along with enterprise-class features from Percona that make it ideal for enterprise production environments.
Percona Server for […]

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PostgreSQL locking, part 3: lightweight locks

LWLocks lightweight locks postgres

PostgreSQL lightweight locks, or LWLocks, control memory access. PostgreSQL uses multi-process architecture and should allow only consistent reads and writes to shared memory structures. LWLocks have two levels of locking: shared and exclusive. It’s also possible to release all acquired LWLocks to simplify clean up. Other databases often call primitives similar to LWLocks “latches”. […]

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PostgreSQL locking, part 2: heavyweight locks

Locking in PostgreSQL

PostgreSQL locking visibility for application developers and DBAs is in most cases related to heavyweight locks. Complex database locking operations require full instrumentation using views from the system catalog. It should be clear which object is locked by a specific database “backend” process. An alternative name for any lock is “bottleneck”. In order to […]

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Reclaiming space on your Docker PMM server deployment

reclaiming space Docker PMM

Recently we had a customer that had issues with a filled disk on the server hosting their Docker pmm-server environment. They were not able to access the web UI, or even stop the pmm-server container because they had filled the /var/ mount point.
Setting correct expectations
The best way to avoid these kinds of issues in […]

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PostgreSQL 11! Our First Take On The New Release

slonik_with_black_text

You may be aware that the new major version of PostgreSQL has been released today. PostgreSQL 11 is going to be one of the most vibrant releases in recent times. It incorporates many features found in proprietary, industry-leading database systems, further qualifying PostgreSQL as a strong open source alternative.
Without further ado, let’s have a […]

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PostgreSQL locking, Part 1: Row Locks

PostgreSQL row level locks

An understanding of PostgreSQL locking is important to build scalable applications and avoid downtime. Modern computers and servers have many CPU cores and it’s possible to execute multiple queries in parallel. Databases containing many consistent structures with changes made by queries or background processes running in parallel could crash a database or even corrupt […]

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Identifying High Load Spots in MySQL Using Slow Query Log and pt-query-digest

pt-query-digest MySQL slow queries

pt-query-digest is one of the most commonly used tool when it comes to query auditing in MySQL®. By default, pt-query-digest reports the top ten queries consuming the most amount of time inside MySQL. A query that takes more time than the set threshold for completion is considered slow but it’s not always true that tuning […]

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How to Fix ProxySQL Configuration When it Won’t Start

restart ProxySQL config

With the exception of the three configuration variables described here, ProxySQL will only parse the configuration files the first time it is started, or if the proxysql.db file is missing for some other reason.
If we want to change any of this data we need to do so via ProxySQL’s admin interface and then save them […]

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Instrumenting Read Only Transactions in InnoDB

Instrumenting read only transactions MySQL

Probably not well known but quite an important optimization was introduced in MySQL 5.6 – reduced overhead for “read only transactions”. While usually by a “transaction” we mean a query or a group of queries that change data, with transaction engines like InnoDB, every data read or write operation is a transaction.
Now, as a […]

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