By SanjayM on May 03, 2013
MySQL Enterprise Backup (MEB) was born 3 years ago as a newly branded avatar of InnoDB Hot backup. Wanted to share what has gone on so far, how we at Oracle think about backup, the milestones that we have achieved and the road ahead. The idea for this blog came to me after looking at Mikael's latest blog. While Mikael talks about MySQL, I want to talk about MEB.
When we started with InnoDB Hot backup the first challenge was to have it adhere to the development, quality and release processes for MySQL. This meant creating a quality plan, getting it into the development trees of MySQL and ensuring that each piece of new code went through architecture and code review. Though the initial implementer and architect of Hot backup continues to work with the MEB team, there were a host of new engineers to be trained. We also needed to ensure that the new (at that time) Barracuda InnoDB file format and incremental backup was supported. MEB 3.5.1 was the release which got these things along with the adherence to the development and quality model of MySQL.
The next challenge we faced was that of ensuring that MEB was on equal footing for both Linux and Windows. InnoDB hot Backup consisted of 2 programs - ibbackup and innobackup; innobackup is a Perl module. The main issue with using the program on Windows was the requirement to install Perl. With multiple Perl implementations and changing Perl versions, we did not want to check MEB compatibility for every implementation and new version of Perl when it was released. Even though the problem is the similar for Linux; the users of Linux are used to hacking around, changing paths and managing multiple versions of software like Perl. Windows users however expect things to just work. So we set about removing the Perl code altogether. This meant that the innobackup functionality had to be re-coded as a C program. Merging these 2 programs meant a major re-think on how the combined command line interface needed to look. The solution we came up with was to let the ibbackup and innobackup command line syntax remain as is, while the combined program had a similar but more logical "mysqlbackup" command line syntax. We were very happy with the new syntax because it freed us from history and MEB syntax became very much in line with the syntax of other MySQL clients. With the release of 3.6 we had a single C program, a more logical syntax , a product which was easier to install and worked exactly the same for all platforms.
We were getting to 2012 and database sizes were commonly approaching the 1 TB size. Such large databases meant the backup should ideally be streamed to tape. Interfacing with tape drives is a complicated and specialized activity. We neither had the bandwidth nor the expertize to handle tapes in MEB. The best solution was to adhere to a good common standard interface that was adopted by software which dealt with tapes. The interface we decided to support was Oracle's System Backup to Tape (SBT) . MEB was modified to be able to to stream the backup output to this interface. A common requirement for these interfaces is that they ideally want to deal with the backup as a single file. A single file can be streamed and restored by any software that speaks SBT. There is a whole ecosystem around SBT because it is the preferred way to backup the Oracle database. Changing MEB to think streaming instead of random access directory output was the challenge we overcame with the release of version 3.7 of MEB. With version 3.7, MEB could interface with Oracle Secure Backup, Symantec Net Backup and Tivoli Storage Manager and any other backup software that understood SBT.
After having resolved what we saw as the "basic" requirements for backup , our customers were demanding more performance and usability. We took up the challenge of performance for the 3.8 version of MEB. MEB was a monolithic single threaded program. We decided to internally break up MEB into 3 separate modules. The read phase, the process phase and the write phase. Each of these 3 phases could be multi-threaded. The number of threads dedicated for each phase were also made user configurable. All operations of backup including the "Applylog" and "copyback" were made multi-threaded. Read more details about this design approach and the performance gains in my blog - Truly Parallel backup. Meanwhile the new release of the MySQL Server 5.6 was also out. It was an interesting challenge to ensure that MEB understood the new MySQL 5.6 features and was able to take advantage of them. As on date MEB 3.8.1 is the only online backup solution that is compatible with the new features of MySQL 5.6.
Backup is like buying insurance. When all else fails you need to be sure that there is a working backup that is available to bring back your database. Backup is not something that can fail when it is needed. It is required that we are surefooted when dealing with such a critical activity. We take your trust in our solution very seriously. Thanks for being a part of the MEB journey (and for reading this blog) so far. The MySQL landscape is ever changing and we know that you desire more usability, performance and flexibility from MEB. We will try and ensure that we meet these expectations with the best possible quality. With every new MEB release you will see a more usable, flexible and performant MEB.