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Displaying posts with tag: ha (reset)

MySQL Cluster - flexibility of replication
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One of the better kept secrets about MySQL Cluster appears to be the flexibility available when setting up replication. Rather than being constrained to implementing a single replication scheme, you can mix and match approaches.

Just about every Cluster deployment will use synchronous replication between the data nodes within a node group to implement High Availability (HA) by making sure that at the point a transaction is committed, the new data is stored in at least 2 physical hosts. Given that MySQL Cluster is usually used to store the data in main memory rather than on disk, this is pretty much mandatory (note that the data changes are still written to disk but that’s done asynchronously to avoid slowing down the database).

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MySQL Proxy - what if it crashes?
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While I hope the MySQL Proxy never crashes, it will happen, there will be some strange (or maybe not so strange) usage or workload and it will die.

To avoid this, you could decide not to use it, or maybe you could use something like Linux HA to have more than one MySQL Proxy running at all times. Or you could use one of the new features that comes with the version 0.7.0.

What is it?
We now have a --keepalive option. As the name indicates, if the mysql proxy process dies/crashes, it will come back up in a few seconds (less than 5 seconds).

How does







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Solaris Cluster + MySQL Demo at a Exhibition Hall near you
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Hi,

If by any chance you are at the MySQL user conference in Santa Clara conference center, there are some great possibilities to see MySQL and Solaris Cluster in action. We have a demo at the exhibition hall, where you can see MySQL with zone cluster and MySQL with SC Geographic Edition.

I will host a birds of a feather at Wednesday 4/22/09 evening in meeting room 205 at 7 pm. The Title is "Configuring MySQL in Open HA Cluster, an Easy Exercise" check out the details here.  I will give a presentation at Thursday 4/23/09 morning 10:50 in Ballroom G, the title is "Solutions for High Availability and

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Solaris Cluster + MySQL Demo at a Exhibition Hall near you
Employee +0 Vote Up -0Vote Down

Hi,

If by any chance you are at the MySQL user conference in Santa Clara conference center, there are some great possibilities to see MySQL and Solaris Cluster in action. We have a demo at the exhibition hall, where you can see MySQL with zone cluster and MySQL with SC Geographic Edition.

I will host a birds of a feather at Wednesday 4/22/09 evening in meeting room 205 at 7 pm. The Title is "Configuring MySQL in Open HA Cluster, an Easy Exercise" check out the details here.  I will give a presentation at Thursday 4/23/09 morning 10:50 in Ballroom G, the title is "Solutions for High

  [Read more...]
Solaris Cluster + MySQL Demo at a Exhibition Hall near you
Employee +0 Vote Up -0Vote Down

Hi,

If by any chance you are at the MySQL user conference in Santa Clara conference center, there are some great possibilities to see MySQL and Solaris Cluster in action. We have a demo at the exhibition hall, where you can see MySQL with zone cluster and MySQL with SC Geographic Edition.

I will host a birds of a feather at Wednesday 4/22/09 evening in meeting room 205 at 7 pm. The Title is "Configuring MySQL in Open HA Cluster, an Easy Exercise" check out the details here.  I will give a presentation at Thursday 4/23/09 morning 10:50 in Ballroom G, the title is "Solutions for High

  [Read more...]
MySQL High availability with VCS cluster
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At MySQL/Sun we do a lot of high availability setup using Heartbeat but recently I was involved, along with Harold Mayfield (a VCS expert), in project using Symantec VCS on Solaris. Of course, MySQL works perfectly well with VCS, here are a few highlights of the installation.

Apart from the share store resources and the IP resources, MySQL is configured as the following:

	Application insiderDB-app (
		StartProgram = "/san/mysql/bin/mysqld --defaults-file=/etc/my.cnf &"
		StopProgram = "/san/mysql/bin/mysqladmin -u root shutdown"
		MonitorProgram = "/san/vcs_scripts/mysql_monitor"
		)

and the mysql_monitor script is the following:

#!/bin/ksh

STATUS=$(/usr/bin/echo status | /san/mysql/bin/mysql -u root 2>/dev/null |/usr/bin/grep -c Uptime) 

if [ "$STATUS" -eq "1" ]
then
	exit 110
else
	exit 100
fi
Social networking type queries with NDB (part 3)
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In the previous 2 posts of this series, we basically talked about how to execute social networking type queries using SQL IN clause and how handle multiple columns IN clause. In this last post on the topic, I will introduce the notion of NDB API filters, although I don’t consider myself as an NDB API expert. Filters are to NDB API the equivalent WHERE clause in SQL. The point is that the filters can be nested and they are sent to the storage nodes only when the transaction is executed.

As an example, let’s consider the following table:

Create Table: CREATE TABLE `MultiColPK` (
  `region_id` int(11) NOT NULL DEFAULT '0',
  `application_id` int(11) NOT NULL DEFAULT '0',
  `first_name` varchar(30) NOT NULL DEFAULT '',
  `payload` varchar(30) DEFAULT NULL,
  PRIMARY KEY
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NDB Cluster one step closer to become a DB killer app!
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If you have been following the development of the NDB Cluster storage engine lately, you are probably as excited as I am. NDB Cluster is becoming a kind of large database killer app. Look at all the nice features that have been added:

  • Replication, if you know MySQL you know what I am talking about
  • Distribution awareness, optimize query execution based on the distribution, a strong scaling factor
  • Disk based data, the possibility of pushing some columns to disk
  • Online add index, among the only online DDL I know of in MySQL
  • Multi-threading, no more need to configure many data nodes per server
  • Realtime, when query execution times matter

and I probably miss some. And now, with version 7 (renamed from 6.4) it is possible to extend a NDB cluster

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Social networking type queries with NDB (part 2)
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Recently, I talked about how to optimize social networking type queries for the NDB storage engine using IN clause statements. In clauses are great but they have one fundamental limitation, they work only on one column (Actually, this is not true, I discovered, thanks to Roland’s comment, that MySQL supports multiple columns IN clause). What if the primary key is a composite of let’s say “region_id”, “application_id” and “user_id”? Recently, while on site with a client, Brian Morin showed me a very clever way of dealing these type of primary keys in an IN clause. The main problem is that you cannot return a binary or varbinary from a function. So the idea was to used the return values of a stored proc. First we need to compose the varbinary from the actual values with this stored proc:
.

delimiter

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High performance replacement of the MySQL Memory storage engine with NDB
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People often wants to use the MySQL memory engine to store web sessions or other similar volatile data.
There are good reasons for that, here are the main ones:

  • Data is volatile, it is not the end of the world if it is lost
  • Elements are accessed by primary key so hash index are good
  • Sessions tables are accessed heavily (reads/writes), using Memory tables save disk IO

Unfortunately, the Memory engine also has some limitations that can prevent its use on a large scale:

  • Bound by the memory of one server
  • Variable length data types like varchar are expanded
  • Bound to the CPU processing of one server
  • The Memory engine only supports table level locking, limiting concurrency

Those limitations can be hit fairly rapidly, especially if the session payload data is large. What is less known is that NDB Cluster can creates


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10 Newer Entries Showing entries 91 to 100 of 123 10 Older Entries

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