What is Digg?38 Comments
- BobbinFrapples, on 10/12/2007, -2/+10priceless
Warning: mysql_connect(): Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug in /var/www/web31/web/includes/database.mysql.inc on line 32
Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug - ddn3d, on 10/12/2007, -3/+5Required reading for anyone about to get digg'ed.
- diecastbeatdown, on 10/12/2007, -1/+3http://www.samag.com/documents/s=10029/sam0604a/0604a.htm
sysadmin article on how to do this.. shows a nice formula for calculating memory needed per node. - joshsz, on 10/12/2007, -1/+3Beware before you use this sort of configuration that there are a few limitations to mysql cluster: for one, you have to have ALL your data in ram at all times. That means if you have 1Gb of ram on your smallest server, your db can never go above ~1Gb in size before you start swapping like crazy. Another thing is that all varchar columns instead of being dynamically sized, will always take up the max space: e.g. if you declare a varchar(50) and a field only has 10 chars in it, it will still be 50 chars long in memory.
This system works really well for smaller db's, and is highly effective, but I'm waiting for the size restrictions to go away before deploying this on my (rather large) installation :).
Btw, you can write to any node with mysql cluster. You had to worry about which node to write to only with a master/slave setup. - squenix1221, on 10/12/2007, -1/+2I got that error too--try to reload, the page loaded successfully the 2nd time
- cyberprashant, on 10/12/2007, -1/+2anyone know what digg itself is using....i'd like to see a "behind the scenes" on digg.
- naros, on 10/12/2007, -2/+3Similiar howto's are located on the MySQL website. Never the less this is a good article. I think MySQL only supports clustering for memory databases only. I could be wrong on this.
- Gargoyle, on 10/12/2007, -1/+2For most applications (few writes, many reads) you would be better off using replication. This would require your software to be aware of a write node and many read nodes, but it's a hell of a lot less complicated than that solution.
- katar, on 10/12/2007, -1/+1The problem is that the SysAdmin article doesn't have the load balancing stuff. Which is really the stuff I wanted to read about. I got in early enough to see page one, but after finishing the first page I just got "Problem loading page" on subsequent pages. :-( Ah well, maybe I'll check it out in a few weeks.
- thecookie, on 10/12/2007, -1/+1Recent research at work concluded that a MySQL cluster shouldn't be used if you want performance, but rather when you need guaranteed availability, when the data should be reachable even if one of the servers die.
Just look at the query timings in an almost empty table! A query like that should be returned in 0.00 sec.
Quote from the article:
mysql> SELECT * FROM testtable;
+------+
| i |
+------+
| 1 |
| 2 |
+------+
2 rows in set (0.17 sec) - tres, on 10/12/2007, -2/+2
Keep in mind that mysql clustering keeps the database in RAM. If the circuit to the rack with your two servers in it dies, your data evaporates. - Numbski, on 10/12/2007, -3/+3The only thing to keep in mind is that you can only write to one node. I would suggest making two dns entries- mysql-write.domain and mysql-read.domain. That way you can simply manage it all.
- neilhan, on 10/12/2007, -0/+0Russ960, The cluster servers should all be in a private network. Only the balance virtual ip is accessible from outside, including internal network. That should solve your concern.
This should also improve performance. Cause the network has less traffic. - llbbl, on 10/12/2007, -1/+1page seems to be working now. looks like a good howto.
- geronimo, on 10/12/2007, -1/+1If anyone posts an analysis of a cluster of postgresql servers using slony I will give them a cookie.
- ashtonium, on 10/12/2007, -1/+1Link via Coral: http://www.howtoforge.com.nyud.net:8090/loadbalanced_mysql_cluster_debian
- hashkaran, on 10/12/2007, -2/+2Digg brought down howtoforge.com
Howtoforget themseleve need to Implement this Mysql clustering solution..
I go this message when i tried to readup.
Warning: mysql_connect(): Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug in /var/www/web31/web/includes/database.mysql.inc on line 32
Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug - diecastbeatdown, on 10/12/2007, -1/+1this is correct. it is a RAM based database, it will do write outs to hard drive preiodically. we were looking at installing one in our data center, but all of our database come to about 1TB total. in other words, the project got canned. ;P
- Brak710101, on 10/12/2007, -1/+1Well, thats not good. I go to see an artical about MySQL server managment, and I get a MySQL error...
I'm guessing the artical needs re-written. - inactive, on 10/12/2007, -1/+1These are always my favorite Dugg stories because it helps me come to terms with how much of a total geek I am actually NOT. I did not understand a single word of the description of that story. May as well have said, "Blah blah blah MySQL."
- inactive, on 10/12/2007, -2/+1some body needs to check their cluster cause it's down and I can't see the site
- neofactor, on 10/12/2007, -4/+3The irony:
"
Warning: mysql_connect(): Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug in /var/www/web31/web/includes/database.mysql.inc on line 32
Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug
" - LaptopHeaven, on 10/12/2007, -1/+0This seems like the same article published in SysAdmin magazine this month. The magazine article is written much better (and the magazine won't crash while your reading!).
- xtr3m, on 10/12/2007, -2/+1This is just funny.
- inactive, on 10/12/2007, -2/+1Dugg because I (and my coworkers) got a laugh about the title linking to a page that has a error :-)
- mweierophinney, on 10/12/2007, -1/+0naros -- There are two types of MySQL clusters. One is the MySQL Cluster product, which, as you mentioned, supports clustering for in-memory databases. The other is a more traditional route where you have a master database and one or more replicated slaves; the master pushes binary updates to each slave as changes come in. The drawback to memory databases is storage and hardware limitations; the drawback to replicated databases is your SPOF in the master DB, and the fact that if you have a lot of write actions going on, replication makes no sense.
- russ960, on 10/12/2007, -1/+0Totally interesting but completely useless since it provides no security. Even if you have this behind a firewall on your private secured network it is totally open to attack from internal users. I wouldn't feel comfortable having all of my sales data, manufacturing data, employee data or whatever unprotected. Not cool...
Dugg for being interesting. Otherwise you might want to stick with Oracle RAC. - echeese, on 10/12/2007, -2/+1Oh, the irony. I love digg sometimes (more than I usually do).
- shortblondemark, on 10/12/2007, -1/+0I may be mistaken, but aren't the RAM requirements actually for the amount of data used by the particular node and not the entire database.
So a 4 node cluster will each handle half the database (1/4 as primary, and 1/4 as backup for another node), and therefore the RAM required will be half the database side.
In the same vain, each machine in a cluster with 16 nodes only uses 1/8 of the RAM for the entire database.
I also believe keeping the database in RAM will no longer be a requirement in 5.1, although again I may be mistaken :) - i77ac10, on 10/12/2007, -1/+0LOL. Dugg. The irony is too good =)
- dude3609, on 10/12/2007, -2/+1dugg for the error.. funny stuff
- KCorax, on 10/12/2007, -3/+1naros you are not harsh enough on the subject.
"can the industry spell P o s t g r e" ?
Oh come on it'll earn you a bottle of warm milk - acespades, on 10/12/2007, -2/+0Until when will people post howtoforge articles here?
- MellerTime, on 10/12/2007, -5/+2Cool. I have no need for clustered MySQL, but looks like a great tutorial I could come back to if I ever found the need.
- Numbski, on 10/12/2007, -5/+1lol. They're not so load balanced themselves. I tried to coralize it, but in vain. :
Warning: mysql_connect(): Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug in /var/www/web31/web/includes/database.mysql.inc on line 32
Can't create a new thread (errno 11). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug - drgori, on 10/12/2007, -6/+1Ironically, the site is currently down because of a problem connecting with MySQL. (And I was looking forward to reading it!)
- naros, on 10/12/2007, -7/+2This is exactly why you should use a database that can handle higher load. PostgreSQL handles load much better.
- pluto124, on 10/12/2007, -6/+1Too funny. I clicked on the article and received a mysql error message. Could not create a new thread. %)
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