Re: RAM-usage and hardware upgrade 10gb RAM
David Griffiths wrote: We just put a new dual-Opteron server into our production environment. We ordered a Megaraid SCSI card and five 10k drives, and a 3Ware Escalade SATA card with six 7200 RPM drives (Maxtor) to see which ones were best. Our network guy did a bunch of benchmarking on the drives and found that SCSI-RAID5 was a bit faster than SATA-RAID0+1. The SATA was significantly cheaper (the 3Ware card was the same price as the Megaraid card, however). You might be able to tie a 10K SCSI rig if you went with the Western Digital Raptor drives. We ended up putting the SATA drives in production - some bug in the SCSI driver kept crashing MySQL on index-creation, etc. High Performance MySQL mentions that SCSI 15K drives are worth the extra money. Thanks David for your post, Does anybody else in this list have experience with SATA-RAIDs? After having done some research it looks like we'll go with a dual-Opteron an 8-12GB of RAM and a SATA-RAID10 with 8-10 250GB-SATA-discs. We are just waiting for the NCQ-SATA-drives to be available and for 2 colleagues to return from vacation since we want everybody to be here when we do that major change. (looks like we'll order the system in 2-3 weeks if the harddiscs are available) Our most important tables that get selects all the time and get updated up to 30 times a second each (or even more often depending on the time of the day) are of a total size of about 5-6 gigs. Is it realistic thinking that mysql/innodb would keep those tables totally in memory and reply to all selects without reading from the disc when we increase innodb_buffer_pool_size to 7 or 8 gigs (assuming we have 12gigs of RAM)? I just wanted to make sure nobody has hit problems with such systems. If you could just send a short We're doing something like that and it works fine I could definitly sleep better ;) thanks for all the posts so far and pointing me towards the right direction! Jan -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: RAM-usage and hardware upgrade 10gb RAM
Jan Kirchhoff [EMAIL PROTECTED] wrote: Money is not really an issue but of course we don't want to waste it for scsi-hardware if we can reach almost the same speed with hardware sata-raids. 'Almost' is a key word. Some SCSI disk are working at 15k RPM, which will give you a HUGE MySQL performance growth compared to 10k disks. AFAIR, there are no 15k RPM SATA disks yet. Money is not really an issue but of course we don't want to waste it for We'd like to stay with x86 because all our hardware is intel/amd and all our servers are running debian-linux. Can we expect better performance or problems using kernel 2.6.x? You can expect better performance on kernel 2.6.x of course, especially on multiple requests. -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.net http://www.ensita.net/ __ ___ ___ __ / |/ /_ __/ __/ __ \/ /Egor Egorov / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.net ___/ www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: RAM-usage and hardware upgrade 10gb RAM
Egor Egorov wrote: Money is not really an issue but of course we don't want to waste it for scsi-hardware if we can reach almost the same speed with hardware sata-raids. 'Almost' is a key word. Some SCSI disk are working at 15k RPM, which will give you a HUGE MySQL performance growth compared to 10k disks. AFAIR, there are no 15k RPM SATA disks yet. But shouldn't a sata-based RAID10 with 8 discs do job as well? writes would be spread on 4 discs... Has anybody experience with those external SCSI-to-SATA RAIDs? A SCSI-solution would cost twice as much, but would it really speed things up compared to a massive use of parallel (raid0) sata-discs? I know disc i/o is the bottleneck in our case, of course we want the fastest disc/raid-system we can possibly get for our money. Is our thinking too simple or shouldn't it be possible to reach the speed of fast scsi-discs by simply taking 2-3 fast sata-discs in a hardware raid0? Our goal is a raid10, so reading should be even faster. Money is not really an issue but of course we don't want to waste it for We'd like to stay with x86 because all our hardware is intel/amd and all our servers are running debian-linux. Can we expect better performance or problems using kernel 2.6.x? You can expect better performance on kernel 2.6.x of course, especially on multiple requests. Has anybody experiences with RAM-usage and cpu-architecture (please have a look at my earlier post)? thanks Jan -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: RAM-usage and hardware upgrade 10gb RAM
The single biggest difference between SATA (or any IDE) and SCSI is command queuing. Command queuing allows the drive to intelligently reorder reads and writes to make things faster. An ATA drive executes a bunch of commands in the order it gets them, which can be slow if it needs to write data on an inside track, then read from and outside track, and back and forth until the both the read and write requests are finished. SCSI will understand that there is a proximity benefit to the commands, so it will reorder the interlaced requests and execute one before the other. Essentially putting part of one request on hold while it does the other. That's an oversimplification of the algorithm of course. Especially since a server system will probably have many more the two interlaced requests. Did you ever try to clean two rooms at once? Put the clothes away in one, then the other. Make the bed in one, then the other. Lots of useless travel time in there. You would probably clean one and then the other. Except if you are vacuuming, then you would probably vacuum both at once, interlacing two similar actions. SATA is catching up though. Seagate has release SATA drives that have command queueing, but I don't know how it compares to SCSI. On Jul 20, 2004, at 10:40 AM, Jan Kirchhoff wrote: But shouldn't a sata-based RAID10 with 8 discs do job as well? writes would be spread on 4 discs... Has anybody experience with those external SCSI-to-SATA RAIDs? A SCSI-solution would cost twice as much, but would it really speed things up compared to a massive use of parallel (raid0) sata-discs? I know disc i/o is the bottleneck in our case, of course we want the fastest disc/raid-system we can possibly get for our money. Is our thinking too simple or shouldn't it be possible to reach the speed of fast scsi-discs by simply taking 2-3 fast sata-discs in a hardware raid0? Our goal is a raid10, so reading should be even faster. -- Brent Baisley Systems Architect Landover Associates, Inc. Search Advisory Services for Advanced Technology Environments p: 212.759.6400/800.759.0577 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: RAM-usage and hardware upgrade 10gb RAM
We just put a new dual-Opteron server into our production environment. We ordered a Megaraid SCSI card and five 10k drives, and a 3Ware Escalade SATA card with six 7200 RPM drives (Maxtor) to see which ones were best. Our network guy did a bunch of benchmarking on the drives and found that SCSI-RAID5 was a bit faster than SATA-RAID0+1. The SATA was significantly cheaper (the 3Ware card was the same price as the Megaraid card, however). You might be able to tie a 10K SCSI rig if you went with the Western Digital Raptor drives. We ended up putting the SATA drives in production - some bug in the SCSI driver kept crashing MySQL on index-creation, etc. High Performance MySQL mentions that SCSI 15K drives are worth the extra money. Fast hard drives are important, but so is lots of RAM (which is where the Opteron shines). In fact, all the benchmarks I've seen show that the Opteron/Athlon architecture beats Intel processors by a 30-odd percent margin if memory serves (note that for some reason, most benchmarks I've seen were on 3.23, which is outdated and not overly usefull). One of our websites serves up 2 million distinct pages per day; the original coders of the site did something dumb and open a new connection to the database for most of those pages (probably about 1.8 million). Even with that additonal load, our Opteron server has an average CPU load of about 10%. David Jan Kirchhoff wrote: Egor Egorov wrote: Money is not really an issue but of course we don't want to waste it for scsi-hardware if we can reach almost the same speed with hardware sata-raids. 'Almost' is a key word. Some SCSI disk are working at 15k RPM, which will give you a HUGE MySQL performance growth compared to 10k disks. AFAIR, there are no 15k RPM SATA disks yet. But shouldn't a sata-based RAID10 with 8 discs do job as well? writes would be spread on 4 discs... Has anybody experience with those external SCSI-to-SATA RAIDs? A SCSI-solution would cost twice as much, but would it really speed things up compared to a massive use of parallel (raid0) sata-discs? I know disc i/o is the bottleneck in our case, of course we want the fastest disc/raid-system we can possibly get for our money. Is our thinking too simple or shouldn't it be possible to reach the speed of fast scsi-discs by simply taking 2-3 fast sata-discs in a hardware raid0? Our goal is a raid10, so reading should be even faster. Money is not really an issue but of course we don't want to waste it for We'd like to stay with x86 because all our hardware is intel/amd and all our servers are running debian-linux. Can we expect better performance or problems using kernel 2.6.x? You can expect better performance on kernel 2.6.x of course, especially on multiple requests. Has anybody experiences with RAM-usage and cpu-architecture (please have a look at my earlier post)? thanks Jan -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: RAM-usage and hardware upgrade 10gb RAM
On Mon, 19 Jul 2004 18:13:36 +0200, Jan Kirchhoff [EMAIL PROTECTED] wrote: Hi, We are currently using a 4.0.16-replication-setup (debian-linux, kernel 2.4.21, xfs) of two 2.4ghz Intel-Pentium4 systems with 3gig RAM each and SCSI-Hardware-Raid, connected via gigabit-ethernet. We are reaching the limit of those systems and are going to buy new hardware as well as upgrade to mysql 4.1.x. We will start testing our applications on 4.1.3 within the next few weeks but our main problem is that we are not quite sure what hardware to buy... We are planning to buy something like a dual-xeon system with 10-16gb of RAM and hardware raid10 with 8 sata-disks and as much cache as possible. Will mysql be able to use the ram efficiently or are we hitting limits? AMD or Intel? 32bit or 64bit? Whatever you do, get a 64 bit system. Opteron recommended, if you really prefer Intel and can get your hands on one of their 64-bit Xeons that is acceptable, although it may take a little longer for Linux to catch up. Even if the software isn't there yet (it is, it may just be a bit of a hassle to all get working), in the worst case you'll have to run it in 32-bit mode until you can figure that out. You can't use more than 2 gig most of the time / close to 4 gig if you hack things up right innodb cache on a 32 bit system. The rest of the memory will be used by the OS (less efficiently than on a 64-bit system though), but that may or may not be as efficient as innodb doing it. That depends a lot on your application's data access patterns. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
RAM-usage and hardware upgrade 10gb RAM
Hi, We are currently using a 4.0.16-replication-setup (debian-linux, kernel 2.4.21, xfs) of two 2.4ghz Intel-Pentium4 systems with 3gig RAM each and SCSI-Hardware-Raid, connected via gigabit-ethernet. We are reaching the limit of those systems and are going to buy new hardware as well as upgrade to mysql 4.1.x. We will start testing our applications on 4.1.3 within the next few weeks but our main problem is that we are not quite sure what hardware to buy... We are planning to buy something like a dual-xeon system with 10-16gb of RAM and hardware raid10 with 8 sata-disks and as much cache as possible. Will mysql be able to use the ram efficiently or are we hitting limits? AMD or Intel? 32bit or 64bit? Money is not really an issue but of course we don't want to waste it for scsi-hardware if we can reach almost the same speed with hardware sata-raids. We'd like to stay with x86 because all our hardware is intel/amd and all our servers are running debian-linux. Can we expect better performance or problems using kernel 2.6.x? If it really adds performance we might change to something else but x86 or change the OS, but definitly not for 2-5%. We are going to keep the old servers as replication-slaves for big, time consuming selects and making backups. We will have around 60,000,000 inserts/updates a day and lots of selects with joins on tables of all sizes (historical tables with 400,000,000 rows as well as small tables with less than 500,000 rows) The whole size of the database will be around 200gb, growing up to 400gb in the next 12 months. We are using innodb because we had big problems with the locking-issues of myisam. Some of the smaller tables that are updated all the time can be kept in memory if possible since its data is also cached/backuped by the applications that insert/update the data. Has anybody experienced problems with a innodb_buffer_pool_size 10gb? Disk-I/O is our main problem since all the updates go to various tables spread on the discs. Since most of the data can be reconstruted in case of a crash it is ok for us to have delayed inserts and inserts being cached in memory. Are there more options for innodb-tables than increasing innodb_buffer_pool_size and setting innodb_flush_log_at_trx_commit=0 that could speed up inserts/updates? thanks for any help/suggestions... Jan -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
