The Case

Securing MySQL is always a challenge. There are general best practices that can be followed for securing your installation, but the more complex setup you have the more likely you are to face some issues which can be difficult to troubleshoot.

We’ve recently been working on a case (thanks Alok Pathak and Janos Ruszo for their major contribution to this case) where MySQL started becoming unavailable when threads activity was high, going beyond a threshold, but not always the same one.

During that time there were many logs like the following, and mysqld was becoming unresponsive for a few seconds.

2019-11-27T10:26:03.476282Z 7736563 [Note] Got an error writing communication packets
2019-11-27T10:26:03.476305Z 7736564 [Note] Got an error writing …

Last week I wrote about aDNS discovery feature in Etcd. As a step in the whole process we need to create DNS records in twindb.com zone. CloudFlare provides rich API to work with it. We wrapped it into a Python module twindb_cloudflare and opensourced it:

• Source code: https://github.com/twindb/twindb_cloudflare
• Documentation: https://twindb-cloudflare.readthedocs.io
• PyPi package: https://pypi.python.org/pypi/twindb_cloudflare

In the post I will show how to use twindb_cloudflare module.

CloudFlare API …

Setting up an etcd cluster with DNS discovery may be challenging. There are several building blocks:

• Etcd – a distributed key value store
• Amazon EC2 – cloud computing provider
• Cloudflare – DNS provider
• Chef – for configuring individual nodes

Each of them has their pitfalls, we will guide you through whole process.

DNS discovery

Any clustered system needs a way to maintain a list of nodes in a cluster. Usually you need to specify all cluster members when starting a node. This is the way zookeeper and consul works. Effectively you have redundancy in configuration – the list of nodes is stored on every node. The list must be consistent and it’s difficult to maintain it especially if the cluster …

The Log Buffer Edition once again is sparkling with some gems, hand-picked from Oracle, SQL Server and MySQL.

Oracle:

• Oracle GoldenGate 12.1.2.1.1  is now certified with Unity 14.10.  With this certification, customers can use Oracle GoldenGate to deliver data to Teradata Unity which can then automate the distribution of data to multiple Teradata databases.
• How do I change DNS servers on Exadata storage servers.
• Flushing Shared Pool Does Not Slow Its Growth.
• …

The Perfect Server - CentOS 7 x86_64 (nginx, Dovecot, ISPConfig 3)

This tutorial shows how to prepare a CentOS 7 x86_64 server for the installation of ISPConfig 3, and how to install ISPConfig 3 on it. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: nginx web server, Postfix mail server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, Mailman, and many more. Since version 3.0.4, ISPConfig comes with full support for the nginx web server in addition to Apache; this tutorial covers the setup of a server that uses nginx, not Apache. The ISPConfig 3 apache perfect server tutorial is available here.

The Perfect Server - Ubuntu 14.10 (nginx, BIND, Dovecot, ISPConfig 3)

This tutorial shows how to prepare an Ubuntu 14.10 (Utopic Unicorn) server (with nginx, BIND, Dovecot) for the installation of ISPConfig 3, and how to install ISPConfig 3. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: Apache or nginx web server, Postfix mail server, Courier or Dovecot IMAP/POP3 server, MySQL, BIND or MyDNS nameserver, PureFTPd, SpamAssassin, ClamAV, and many more. This setup covers nginx (instead of Apache), BIND (instead of MyDNS), and Dovecot (instead of Courier).

The Perfect Server - Ubuntu 14.10 with Apache, PHP, MySQL, PureFTPD, BIND, Postfix, Dovecot and ISPConfig

This tutorial shows how to install an Ubuntu 14.10 (Utopic  Unicorn) server (with Apache2, BIND, Dovecot) for the installation of ISPConfig 3, and how to install ISPConfig 3. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: Apache or nginx web server, Postfix mail server, Courier or Dovecot IMAP/POP3 server, MySQL, BIND or MyDNS nameserver, PureFTPd, SpamAssassin, ClamAV, and many more. This setup covers the installation of Apache (instead of nginx), BIND (instead of MyDNS), and Dovecot (instead of Courier).

The Perfect Server – CentOS 7 (Apache2, Dovecot, ISPConfig 3)

This tutorial shows how to prepare a CentOS 7 x86_64 server for the installation of ISPConfig 3 and how to install ISPConfig 3. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: Apache web server, Postfix mail server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, Mailman, and many more.

There have been many articles about the downtime issue with Cloudflare last week, so I won’t get into the technical details of that. However, there’s the fine print to remember. Consider this a subtle reminder that core Internet infrastructure services like Cloudflare’s DNS-based “Always Online” caching and packet inspection security services do not come with Service Level Agreements even at the “Pro” account level. Even with a Pro account you are paying for a service with no uptime guarantee and you must only hope that it resolves your sites the majority of the time. This is fine, this is what the contract says: no SLA unless you pay for the Business account. An odd naming convention given that most Professionals are using their websites for business and would want the SLA, but I digress.

So, the SLA is not really the issue if you look at the architectural alternatives to building an architecture that desires availability when …

I haven't written in a while. Some of the reason is that life has been incredibly busy with two young children. The other reason is that I've been busy at work with my team developing HP Cloud DNS, a service that runs in the cloud, as do the various other applications within the Platform as a Service group that I am part of. After a period of rapid development and deployment, Cloud DNS recently went into private beta . The ability to build an cloud application such as this was primarily that I have a great team (Kiall Mac Innes, Simon McCartney and a great product manger Josh Barry) as well as having chosen the right tools and software solutions. For the deployment side of things, Chef, despite frustrations that I have had before getting my mind around it, was a solution that I knew would make it so we could deploy anywhere, as well as being what HPCS uses for their deployments for …