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Showing entries 1 to 10 of 33574 10 Older Entries
Orchestrator 1.2.9 GA released
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Orchestrator 1.2.9 GA has been released. Noteworthy:

  • Added "ReadOnly" (true/false) configuration param. You can have orchestrator completely read-only
  • Added "AuthenticationMethod": "multi": works like BasicAuth (your normal HTTP user+password) only it also accepts the special user called "readonly", which, surprise, can only view and not modify
  • Centralized/serialized most backend database writes (with …
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Making HAProxy 1.5 replication lag aware in MySQL
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HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes. The same approach can be used in a regular master-slaves setup to spread the read load across multiple slaves. However with MySQL replication, another factor comes into play: replication lag. In this case the approach mentioned for  …

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Drop Table slow
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A few days back we were given a MySQL database hosted in EC2 with around 5TB data to move some of the tables to a new server.  The intention was to share the tables between 2 EC2 instances. Since AWS had the option to take online snapshots, the plan was to take a snapshot, create a new machine with that snapshot and drop the unwanted tables.So everything went as planned until creating a new machine with the snapshot.  The real challenge was dropping the unwanted tables.  It took around 4 minutes to Drop a table whose size is 20GB.  It took 20 minutes to drop a 100GB table. The time kept on increasing for larger tables. MySQL even went to …

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Monitor MySQL Performance Interactively With VividCortex
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If you’re monitoring MySQL performance on dozens or hundreds of servers, chances are you have a “rainbow chart” – a time-series chart with hundreds of tiny area graphs stacked on top of each other, crawling imperceptibly one pixel at a time across the big-screen monitor in your office. The trouble with these charts is they’re hard to see. It takes many minutes for enough new pixels to display after a change. In the meantime you can’t see the change clearly.

At VividCortex, we think we’ve found a better way to keep tabs on what’s going on in your infrastructure: a bubble visualization. It is compact, and …

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Scaling TokuDB Performance with Binlog Group Commit
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TokuDB offers high throughput for write intensive applications, and the throughput scales with the number of concurrent clients.  However, when the binary log is turned on, TokuDB 7.5.2 throughput suffers.  The throughput scaling problem is caused by a poor interaction between the binary log group commit algorithm in MySQL 5.6 and the way TokuDB commits transactions.   TokuDB 7.5.4 for Percona Server 5.6 fixes this problem, and the result is roughly an order of magnitude increase in SysBench throughput for in memory workloads.

MySQL uses two phase commit protocol to synchronize the MySQL binary log with the …

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InnoDB’s multi-versioning handling can be Achilles’ heel
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I believe InnoDB storage engine architecture is great for a lot of online workloads, however, there are no silver bullets in technology and all design choices have their trade offs. In this blog post I’m going to talk about one important InnoDB limitation that you should consider.

InnoDB is a multiversion concurrency control (MVCC) storage engine which means many versions of the single row can exist at the same time. In fact there can be a huge amount of such row versions. Depending on the isolation mode you have chosen, InnoDB might have to keep all row versions going back to the earliest active read view, but at the very …

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New Webinar: A DevOps Guide to Database Infrastructure Automation for eCommerce
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December 17, 2014 By Severalnines

For an online shop, the website is the cash register. It has to be open for business 24 hours a day.

As the ops person on duty, when you get a call at 3am after your website went down, your priority number one is to restore the service asap. But why can we not have our application stack automatically recover, and not have the pager wake us at all? Why do we still stick to tedious manual processes, which take up time and resources, and hinder future growth?

Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in …

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Memory summary tables in Performance Schema in MySQL 5.7
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One of great innovation in MySQL 5.7 is memory summary tables в Performance Schema and corresponding views in sys schema

And as troubleshooting freak I have huge reason to greet this feature.

Before version 5.7 we had very limited abilities to diagnose memory issues in MySQL. We could use operating system tools, such as vmstat, top, free, but they only showed what MySQL server uses memory, but do not show how. In version 5.7 things changed. …



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How to install osCommerce on Ubuntu 14.04 (Trusty Tahr)
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How to install osCommerce on Ubuntu 14.04 (Trusty Tahr)

This document describes how to install osCommerce in Ubuntu 14.04. Open Source Commerce (osCommerce) is a popular e-Commerce and online store-management software program that may be easily used on any web server with PHP and MySQL installed. osCommerce is available to users as a free software under the General Public License (GNU) The versatile and fuss-free software enables easy setting up and maintenance of e-stores using minimal effort. This tutorial describes the process of installing osCommerce on Ubuntu 14.04.

December Tip of the Month: Find Queries that Lack Indexes
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It’s an ancient tradition amongst MySQL DBAs to analyze slow query log files and sort the results by the so-called “index ratio” to find badly indexed queries. The “index ratio,” in this case, is a heuristic derived from the ratio of rows read to rows returned. The thinking goes that if a query is reading lots of rows and returning only a few, it might be missing an index.

The trouble with this is that it’s very prone to false positives: GROUP BY queries, for example, will often read lots of rows and aggregate them into few.

Instead of relying on a surrogate measure such as this sometimes-accidentally-right ratio, why not get the …

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Showing entries 1 to 10 of 33574 10 Older Entries

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