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Displaying posts with tag: server (reset)
Restore data from InnoDB file (idb & frm) using TwinDB toolkit

We have been told many times that modifying live database should be done with extreme care, we should always make a backup before doing something big to the database. However, there are countless stories on the Internet about losing data due to various reason, one of them is forgetting to create a backup (Gitlab is an example: https://about.gitlab.com/2017/02/01/gitlab-dot-com-database-incident/). I was facing the same issue when upgrading MySQL server to a new version. Luckily I was able to restore most of the data but it was still a very good lesson for me. One of lesson I learned is how we could restore the data from the *.ibd and *.frm file.

The database I worked with had many tables. There were about 5 of them using MyISAM engine while others were using InnoDB engine. I was asked to upgrade the entire the …

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Concurrent sandbox deployment


Version 0.3.0 of dbdeployer has gained the ability of deploying multiple sandboxes concurrently. Whenever we deploy a group of sandboxes (replication, multiple) we can use the --concurrent flag, telling dbdeployer that it should run operations concurrently.

What happens when a single sandbox gets deployed? There are six sets of operations:

  1. Create the sandbox directory and write down its scripts;
  2. Run the initialisation script;
  3. Start the database server;
  4. Run the pre-grants SQL commands (if any;)
  5. Load the grants;
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Monitoring RDS MySQL Performance Metrics

Amazon Web Services (AWS) is a cloud platform that offers a wide variety of services including computing power, database storage, content delivery and other functionality that targets businesses of all sizes. One of their database solutions includes the Amazon Relational Database Service. Amazon RDS includes a number of popular RDBMSes, including Amazon Aurora, PostgreSQL, MySQL, MariaDB, Oracle, and Microsoft SQL Server, as well as tools to manage your databases and monitor their performance.

Despite the wide range of metrics available within the Amazon RDS console, there are some very good reasons for using your own monitoring tool(s) instead or in addition to those offered by Amazon RDS. For example, familiarity with your own tool(s) or access to features that Amazon RDS does not provide would constitute two persuasive reasons for employing a local tool.

With traditional software monitoring platforms such as Monyog still enjoying …

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Common DNS configuration issues

DNS is one of the most fundamental parts of a website. No website can run without a proper configuration on DNS. For beginners, it might be a bit difficult for them to understand and resolve DNS-related issues. This post aims to provide a bit more help for those who are still struggling to configure the DNS for their websites.

In short, what is DNS and why we need it?

DNS stands for Domain Name Service. You can think of it as a computer responsible for converting the domain name to an IP address. For example, if I type facebook.com into my browser, the DNS will look into its database and return the IP address of this domain, which is 66.220.158.68. Because of this, most of the issues about the domain name of your websites are related to DNS.

We need DNS because our human memory is limited and we cannot remember all complex and meaningless IP addresses of all websites in the world. It is just like …

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How MaxScale monitors servers

In this post, we’ll address how MaxScale monitors servers. We saw in the

We saw in the previous post how we could deal with high availability (HA) and read-write split using MaxScale.

If you remember from the previous post, we used this section to monitor replication:

[Replication Monitor]
type=monitor
module=mysqlmon
servers=percona1, percona2, percona3
user=maxscale
passwd=264D375EC77998F13F4D0EC739AABAD4
monitor_interval=1000
script=/usr/local/bin/failover.sh
events=master_down

But what are we monitoring? We are monitoring the assignment of master and slave roles inside MaxScale according to the actual replication tree in the cluster using the …

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Understanding things inside ~/.ssh

We have been using SSH all the time but not all people really understand the files we put inside the ~/.ssh folder on our computer. It was a myth to me when I was first using SSH, but things are pretty clear to me now and I want to share this with all of you, just in case you don't know.

known_hosts

This file is responsible for verifying the host we have connected to. If it was the first time you connect to a host, you would probably see the following message:

The authenticity of host 'example.com (10.0.0.0)' can't be established.
RSA key fingerprint is    SHA256:VqgUG8v+gxrigR1csELYv6Un6l7HxMgPgMj9wyUr7G4.
Are you sure you want to continue connecting (yes/no)?

The moment you select yes to continue connecting, the hostname along with the public key of the server will be saved as a new line in this file. Why we need this file? Just imagine that for some reason our routing has …

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How to test if CVE-2015-0204 FREAK SSL security flaw affects you

The CVE-2015-0204 FREAK SSL vulnerability abuses intentionally weak “EXPORT” ciphers which could be used to perform a transparent Man In The Middle attack. (We seem to be continually bombarded with not only SSL vulnerabilities but the need to name vulnerabilities with increasing odd names.)

Is your server vulnerable?

This can be tested using the following GIST

If the result is 0; the server is not providing the EXPORT cipher; and as such is not vulnerable.

Is your client vulnerable?

Point your client to https://oneiroi.co.uk:4443/test if this returns “Vulnerable” then the client is vulnerable, if you find a connection error your client should not be vulnerable for example:

root@host:/tmp$ openssl …

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Configuring MySQL Server for Optimal Performance

Configuring MySQL Server, with the dozens of options available, has always been perceived as a bit of a black art. In MySQL Database 5.6, configuring your MySQL server for optimal performance is easier than ever before.

In the MySQL for Database Administrators course you can learn more.

MySQL 5.6 is configured to work faster out of the box in a wide range of installation scenarios and it is easier than ever to set up the server by adjusting only a small number of settings which cause others to be set. In addition, you get a new default my.cnf file with instructions guiding your through adjusting key settings. The …

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Recent MySQL Announced Releases

Recently a several releases of MySQL Server were announced to our mailing lists. Do not miss following news:

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MySQL as a Key Value Store (KVS) - Why, some background and some more tests

You might have seen my attempts at testing MySQL as a Key Value Store (KVS) (here and here), i.e. used like MongoDB, and I have had some comments to those. Above all, many wanted to know the details of my test environment. To be honest, this started off as a very simple thing, but it turned out a bigger than I thought, so I guess its reasonable to give some background. I apologize for not giving you this background before, but as I said, my initial intention was to just run bog standard MongoDB versus MySQL and see what happened.BackgroundHere at Recorded Future, when I joined about 2 …

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