Auf der FrOSCon 10 in St. Augustin habe ich kürzlich ein Update zu unseren Erfahrungen mit dem Thema "Private Cloud mit OpenSource" gegeben. Leider sind noch nicht alle Probleme, über die letztes Jahr berichtet wurde, behoben, aber wir sind schon ein gutes Stück weiter und haben neue Stolperfallen gefunden und z. T. auch überwunden.

Leider habe ich mich mit der Zeit ein wenig getäuscht, da ich den Talk vorher schon einmal in gekürzter Form in 40 Minuten unterbringen musste, aber in der Präsentation den Countdown für die FrOSCon wieder auf 60 Minuten zu stellen vergessen hatte. Zwischenzeitlich war ich deswegen der Meinung, ziemlich hinterherzuhängen... Hoffe, es macht trotzdem ein bisschen Spaß, so blieb am Ende mehr Zeit für Fragen und Gespräche :)

Hier noch die Folien auf Slideshare:

…

Over on the codecentric blog I just published a new post on True KVM Live Migration with OpenStack Icehouse and Ceph based VM storage, outlining the process it took me to get this actually working. There were several issues to work around, some of them bugs in OpenStack, some of them home-grown issues.

I provide a few patches to OpenStack classes as well as a description of what is actually going wrong and how to circumvent the problems. So head right over and have fun reading :)

Today as i was learning for the new MySQL 5.6-certification (more about that in a later post) i stumbled again across the host_cache-Table that was added to MySQL in 5.6.5. Before that you had no chance to check which hosts are already known by the MySQL-server.

So thats a pretty good feature for us. And even better: you could resize the size of the host_cache now! Whoohoo, awesome! As we have a lot of servers that need to connect to one of our MySQL-server and we could not switch to ip-based-authentication we were really happy to tune the host_cache-size without recompiling MySQL.

Unfortunately i noticed that the performance_schema.host_cache table only holds 128 rows and that the content was changing everytime i checked. So i logged in to a server that wasn’t already in the host_cache-table, made a connection attempt to the mysql server  and checked again the host_cache-table:

The server was now in the …

Recently i updated to MySQL 5.6 and we were really excited about the very good overall performance. But beside a major bug concerning wrong results when running a SELECT that includes a HAVING based on a function (see http://bugs.mysql.com/bug.php?id=69638) we also noticed that from time to time the replication breaks with the following error:

Last_SQL_Errno: 1590
Last_SQL_Error: The incident LOST_EVENTS occured on the master. Message: error writing to the binary log

After some investigation it seemed like this happens if one modifies some user privileges, so we stumbled upon http://bugs.mysql.com/bug.php?id=68892.

Essentially the bug report says that if you use the wrong syntax for GRANT-statements the replication will break. So far, so bad. I told everyone who had the …

This is MySQL's Bad Idea #573 (after #384, which I've blogged about before) I've just had a terrible experience with a bug report from the jOOQ User Group, related to escaping of backslashes in string literals in MySQL. First, I thought to myself, whatever. SQL doesn't escape backslashes. The only escape character within a string … Continue reading MySQL Bad Idea #573 →

Here is a fix for the MySQL/TokuDB/MariaDB bug I reported earlier today.  I think this fix is correct (it is only one line) but I don’t delve into the storage engine very often (and particularly not into ha_partition.cc) so I think it would be good to wait for Oracle (or Percona, MariaDB, or Tokutek) to validate that it is correct before using it.

diff -u ha_partition.cc /tmp/ha_partition.cc 
--- ha_partition.cc 2013-04-05 05:27:18.000000000 -0700
+++ /tmp/ha_partition.cc 2013-05-27 02:45:01.680676228 -0700
@@ -6455,9 +6455,11 @@
void ha_partition::get_dynamic_partition_info(PARTITION_STATS *stat_info,
uint part_id)
{
+
handler *file= m_file[part_id];
DBUG_ASSERT(bitmap_is_set(&(m_part_info->read_partitions), part_id));
- file->info(HA_STATUS_CONST | HA_STATUS_TIME | HA_STATUS_VARIABLE |
+ 
+ info(HA_STATUS_CONST | HA_STATUS_TIME | HA_STATUS_VARIABLE |
HA_STATUS_VARIABLE_EXTRA | HA_STATUS_NO_LOCK);
stat_info->records= …

Recently I happen to setup a new MySQL instance with my tools – a standard MySQL 5.1+, xtrabackup setup and last-hotbackup.tar.gz. To restore from the backup we used xtrabackup binaries…

The post xtrabackup_51: not found & no ‘mysqld’ group in MySQL options first appeared on Change Is Inevitable.

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Got a packet bigger than ‘slave_max_allowed_packet’ bytes and binlog_format=STATEMENT|MIXED

Since version 5.1.64 MySQL introduces a new variable named slave_max_allowed_packet, which was introduced to allow large updates using row-based replication do not cause replication to fail when exceeded max_allowed_packet.

The problem is if you have you replication using binlog_format=STATEMENT or binlog_format=MIXED it ignores this option and use as limit for queries what is on max_allowed_packet variable but still reporting on slave_max_allowed_packet causing the IO_THREAD to report the wrong message.

Solution:
Run the …

I have been meaning to write this down for quite some time, but it always eluded me. When you are using Time Machine to back up your Mac, you get the chance of password-protecting your backups.

Whenever the machine is restarted you will have to unlock the disk by entering the password, unless you store the password for the backup disk in your keychain. For paranoia's sake (and to keep the password fresh in my memory, just in case) I do not store the password in the keychain.

Now, what happens quite regularly to me is this: I reboot the machine for some reason or other, and while it is doing that, I leave the room and do something else. Before I know it, maybe an hour has passed before I come back. In the meantime, the external Time Machine drive has gone to sleep, because it was not used for an extended period of time. On the screen, there is the password dialog dutifully waiting for me to unlock the protected volume.

As …

We’re always testing the latest versions of MySQL with most of the environments to make sure that we can find the critical issues before it goes to production. This wasn’t different with the 5.6 MySQL neither. We already started to play with this version in the summer. The first news were very promising. The performance gain is significant. However we have run into couple of errors. One of them was the

mysql_install_db problem with replicating environment

[root@hostname ~]# mysql_install_db --user=mysql --datadir=/mysql/data/

------------------------------------------------------------------------------------
Installing MySQL system tables...
121217 10:02:20 InnoDB: The InnoDB memory heap is disabled
121217 10:02:20 InnoDB: Mutexes and rw_locks use GCC atomic builtins
121217 10:02:20 InnoDB: Compressed tables use zlib 1.2.3
121217 10:02:20 InnoDB: Using Linux native AIO
121217 10:02:20 InnoDB: CPU supports crc32 instructions
121217 10:02:20 …