VividCortex is designed to offer its users as much access and visibility into their database systems as possible. With that in mind, we're excited to let all of our MongoDB users know that VividCortex is capable of capturing, displaying, and navigating metrics and charts produced in MongoDB's powerful WiredTiger storage engine. 

Beginning with MongoDB version 3.0, users will have the option of selecting one of two storage engines: the default MMAPv1 engine, as used in prior MongoDB releases; or the new WiredTiger engine. As MongoDB's site explains,

For many applications, WiredTiger's more granular concurrency control and native compression will provide significant benefits in the areas of lower storage costs, greater …

We were just leafing through the 2015 edition of The DZone Guide to Database and Persistence Management, and we noticed some interesting stats in the guide's included survey, about which we'd like to share some observations. The survey is one of the ebook's central features, and it includes feedback from over 800 IT Professionals, with 63% of those respondents coming from companies with over 100 employees and 69% with over 10 years of experience -- they represent a significant and important cross-section of our industry.

These kinds of reports can be enlightening, as they offer the opportunity to take some of our principles and pin them to the hard facts and numbers of actual database activity, in the field. 

In a section titled "One Type of Database is Usually Not Enough," the report reveals that it's stadard …

I lost count of the number of times I had customers come to me for a regular MySQL performance check-up saying “no, we don’t have any performance problems right now”, just to find they do actually have them, they’re just not aware of it. It’s no big surprise this happens when you’re not using your system as actively as your users are.

So let me share with you one trick I’m using to quickly check if the system I’m on has any problems that need troubleshooting. Actually, it’s dead simple. And no, it’s not a slow query log, it’s Threads_running. Let me show you.

Wait, what’s wrong with the slow query log?

Nothing at all. MySQL’s slow query log is a great tool when you’re looking for slow queries. Or when you’re fishing for things to optimize – either to reduce the resource consumption, or to increase speed for queries you didn’t know are slow.

And it’s …

PGConf Silicon Valley was excellent this year: good organization, great speakers, and top-notch vibes in general. We were excited to see everybody visiting (and crowding!) our booth and the overall very positive community presence. Highlights included a presentation about Postgres' use at TripAdvisor, a look at Amazon RDS for Postgres, and consideration of system scalability and the future of relational database management systems.

Baron Schwartz, VividCortex's own founder and CEO, was at the Silicon Valley conference, and he's said that it was the best PGConf he's been to yet. On November 18th, Baron even led a breakout session, titled "Analyzing PostgreSQL Network Traffic with vc-pgsql-sniffer," in which he explained both the principles and practice that come together to result in VividCortex's powerful sniffer tools. Even the questions asked at Baron's talk were fantastic.

To watch a video of Baron's breakout session, find …

We've talked a lot about the high-resolution data we capture, but if you haven't experienced it yourself, it might be a little abstract. Here, look at the difference between 1-second and 1-minute data.

Are your monitoring systems glossing over important detail with low-frequency data?

All of our metrics are in 1-second granularity. That's 60x more data points per minute than most monitoring tools. It's 120x more data points per second than MongoDB Monitoring Service's premium paid tier. It's 500x more data points per minute than MySQL Enterprise Monitor at its default settings.

It's enough detail to see 1-second server stalls you will never find otherwise. This gives you the ability to proactively find and stop problems that will become much more serious over time.

And this data is not only realtime but …

Ever get called out for a MySQL issue only to realize that there was no issue?  It was a false alarm from the monitor.  We sure have and it’s frustrating, especially at 3:00 or 4:00 in the morning!

Many DBAs work in an environment where there is some sort of first level support that gets assigned tickets first.  Unfortunately, many of the times these groups are, shall we say, less than skilled in MySQL.  As a result, they quickly escalate the ticket onto the primary on-call DBA, even when there is really nothing wrong.

Much of the time, there are multiple types of MySQL topology in these environments: standalone, galera cluster, replication, etc.  Writing large runbooks with detailed test cases can be a daunting process and one that will cause many first-level support engineers to give up and simply escalate the issue anyway.

In an effort to avoid undue call outs, we developed a simple bash …

The MySQL server supports a variety of client connection methods. To summarize: you have TCP/IP (v4 and v6) on all OSes (with or without TLS/SSL encryption), Unix Domain Sockets on Unix/Linux, and Named Pipes and/or Shared Memory on Windows.

Each of these connection methods has its own set of pros and cons: speed, security, portability, and ease-of-use.…

Previous episodes:

• MySQL replication monitoring 101

MySQL replication in action - Part 1: GTID & CoMySQL replication in action - Part 2 - Fan-in topologyMySQL replication in action - Part 3 - All-masters P2P topologyMySQL replication in action - Part 4 - star and hybrid topologies
Parallel replication overviewOne of …

In the theoretical part of this series, we have seen the basics of monitoring. In that article, though, we have barely mentioned the new tools available in MySQL 5.7 and MariaDB 10. Let’s start from something that has the potential of dramatically changing replication as we know it.
Crash-safe tables and Global transaction identifiers in MySQL 5.6 and 5.7Global transaction identifiers (GTID) is a feature that has been in my wish list for long time, since the times I was working with the MySQL team. By the time I left Oracle, this feature was not even in the plans.
When MySQL 5.6 was first disclosed, the biggest improvement for replication was the introduction of crash-safe tables (see Status persistence in …

Replication is the process that transfers data from an active master to a slave server, which reproduces the data stream to achieve, as best as possible, a faithful copy of the data in the master.

To check replication health, you may start with sampling the service, i.e. committing some Sentinel value in the master and retrieving it from the slave.

Sentinel data: Tap tap… Is this thing on?
If you want to make sure that replication is working, the easiest test is using replication itself to see if data is being copied across from the master to the slaves. The method is easy:

1. Make sure that the data you want to see is NOT in the master or in the slave. If you skip this step, you may think that replication is working, while in fact it may not.
2. Either create a table …