I recently had the chance to play with the new T5140 servers. Using the Sparc CMT architecture, these servers present an amazing 128 cpu's to you to use (as a combination of cores and compute threads, there are 2 sockets only).

We are doing some trials with eager Sun customers who want to utilize these babies. The good news is that MySQL Cluster 7.0 (aka 6.4) will support a multi-threaded data node option. The bad news is, one ndbd process still only uses about 8 CPU cores, so to utilize 128, there is some way to go! So the bad news is we still have to launch many ndbd processes to get out the full power of these boxes. But the good news is that with 7.0 there is at least a point in trying at all.

I developed a simple script which lets me easily start a varying amount of ndbd and mysqld processes on one host (and then copy the script to also start same amount of processes on another host). If you have been using Johan's excellent …

I recently had the chance to play with the new T5140 servers. Using the Sparc CMT architecture, these servers present an amazing 128 cpu's to you to use (as a combination of cores and compute threads, there are 2 sockets only).

We are doing some trials with eager Sun customers who want to utilize these babies. The good news is that MySQL Cluster 7.0 (aka 6.4) will support a multi-threaded data node option. The bad news is, one ndbd process still only uses about 8 CPU cores, so to utilize 128, there is some way to go! So the bad news is we still have to launch many ndbd processes to get out the full power of these boxes. But the good news is that with 7.0 there is at least a point in trying at all.

I developed a simple script which lets me easily start a varying amount of ndbd and mysqld processes on one host (and then copy the script to also start same amount of processes on another host). If you have been using Johan's excellent …

I recently had the chance to play with the new T5140 servers. Using the Sparc CMT architecture, these servers present an amazing 128 cpu's to you to use (as a combination of cores and compute threads, there are 2 sockets only).

We are doing some trials with eager Sun customers who want to utilize these babies. The good news is that MySQL Cluster 7.0 (aka 6.4) will support a multi-threaded data node option. The bad news is, one ndbd process still only uses about 8 CPU cores, so to utilize 128, there is some way to go! So the bad news is we still have to launch many ndbd processes to get out the full power of these boxes. But the good news is that with 7.0 there is at least a point in trying at all.

I developed a simple script which lets me easily start a varying amount of ndbd and mysqld processes on one host (and then copy the script to also start same amount of processes on another host). If you have been using Johan's excellent …

One thing we were guessing at with Massimo yesterday is, if you store
large blobs as disk data, how much will they consume DataMemory and
IndexMemory (primary key, each "chunk" has a hidden primary key, first 25x bytes
of blob stored in memory...)?

My empirical test showed that about 2% of the total size of blobs is needed for RAM
(25% of that is IndexMemory).

IMHO this is close to negligible, but in many situations not negligible
at all (may have close to TB of disk data -> 20GB of RAM needed for
disk data).

Also note that this is a minimum figure. If you actually have something
else than the blob (like other indexes) you of course use much more RAM.

The test was:
CREATE TABLE `jpgtest` (
`id` int(11) NOT NULL,
`jpg` blob,
PRIMARY KEY (`id`)
) TABLESPACE ts_1 STORAGE DISK ENGINE=ndbcluster;

One thing we were guessing at with Massimo yesterday is, if you store
large blobs as disk data, how much will they consume DataMemory and
IndexMemory (primary key, each "chunk" has a hidden primary key, first 25x bytes
of blob stored in memory...)?

My empirical test showed that about 2% of the total size of blobs is needed for RAM
(25% of that is IndexMemory).

IMHO this is close to negligible, but in many situations not negligible
at all (may have close to TB of disk data -> 20GB of RAM needed for
disk data).

Also note that this is a minimum figure. If you actually have something
else than the blob (like other indexes) you of course use much more RAM.

The test was:
CREATE TABLE `jpgtest` (
`id` int(11) NOT NULL,
`jpg` blob,
PRIMARY KEY (`id`)
) TABLESPACE ts_1 STORAGE DISK ENGINE=ndbcluster;

One thing we were guessing at with Massimo yesterday is, if you store
large blobs as disk data, how much will they consume DataMemory and
IndexMemory (primary key, each "chunk" has a hidden primary key, first 25x bytes
of blob stored in memory...)?

My empirical test showed that about 2% of the total size of blobs is needed for RAM
(25% of that is IndexMemory).

IMHO this is close to negligible, but in many situations not negligible
at all (may have close to TB of disk data -> 20GB of RAM needed for
disk data).

Also note that this is a minimum figure. If you actually have something
else than the blob (like other indexes) you of course use much more RAM.

The test was:
CREATE TABLE `jpgtest` (
`id` int(11) NOT NULL,
`jpg` blob,
PRIMARY KEY (`id`)
) TABLESPACE ts_1 STORAGE DISK ENGINE=ndbcluster;

Last week I helped a customer setup a JBoss application against MySQL Cluster. It turns out it is not immediately obvious how you should setup our JDBC connector to do loadbalancing and failover. For instance, setting the connector up for an Master-Slave setup (with MySQL Enterprise) is well documented, but not doing the same with MySQL Cluster.

It's not really properly documented in the manual part, but I found in the changelogs, and confirmed on IRC that to do load-balancing across the SQL nodes in MySQL Cluster, you would use a different JDBC connection string with the "loadbalance" keyword added...

jdbc:mysql:loadbalance://host-1,host-2,...host-n/database

That does indeed …

Last week I helped a customer setup a JBoss application against MySQL Cluster. It turns out it is not immediately obvious how you should setup our JDBC connector to do loadbalancing and failover. For instance, setting the connector up for an Master-Slave setup (with MySQL Enterprise) is well documented, but not doing the same with MySQL Cluster.

It's not really properly documented in the manual part, but I found in the changelogs, and confirmed on IRC that to do load-balancing across the SQL nodes in MySQL Cluster, you would use a different JDBC connection string with the "loadbalance" keyword added...

jdbc:mysql:loadbalance://host-1,host-2,...host-n/database

That does indeed …

Last week I helped a customer setup a JBoss application against MySQL Cluster. It turns out it is not immediately obvious how you should setup our JDBC connector to do loadbalancing and failover. For instance, setting the connector up for an Master-Slave setup (with MySQL Enterprise) is well documented, but not doing the same with MySQL Cluster.

It's not really properly documented in the manual part, but I found in the changelogs, and confirmed on IRC that to do load-balancing across the SQL nodes in MySQL Cluster, you would use a different JDBC connection string with the "loadbalance" keyword added...

jdbc:mysql:loadbalance://host-1,host-2,...host-n/database

That does indeed …

In the previous post we had a look at the MySQL Cluster NDB API and how it enables direct access to the MySQL Cluster data nodes, and therefore also enables access through other protocols than SQL.

I've often asked myself: Since NDB is so great for MySQL Cluster, is there anything similar for MySQL Server (the not-cluster version...)? A couple of months ago Kazuho Oku did something like that and wrote in his blog about it.

The context for Kazuho's work is the social network use case: 1) You have users. 2) Some users are linked to each others as friends. 3) When a user logs in, he should see a timeline of events/messages from his friends. In a previous post he had already tested the difference between a …