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My current VPS (5 node tmdhosting VPS) is very slow on disk IO throughput; a simple insert mysql query can take more than 10 seconds ( yes, more than 10 seconds!!) to complete. I've checked already, my VPS is underutilized, and I strongly suspect that other VPSes that cohabitate with mine on the same physical server is doing a lot of disk IO operation at the expense of mine.

Not only that, the performance of mysql write query can be quite inconsistent; on a day it is fast, and on another day it is slow. This is also reinforcing my above suspicion.

I am thinking about switching to cloud hosting. But I afraid that cloud hosting may have the same problem ( ie: IO throughput is shared among all of the visualization), am I right in this?

Is there any kind of hosting package that I can use to get a consistent IO throughput? I understand that dedicated server is the ultimate answer, but I don't want to use a dedicated server just yet.

Graviton
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  • It seems you've fallen victim to overselling. I'd find a different host. There are plenty out there. – Nathan C Aug 28 '13 at 10:55
  • @NathanC, I could find a different host, but the very same host can also oversell me – Graviton Aug 28 '13 at 11:11
  • They could, but the fact remains that as a customer of your current host the 2 solutions available to you are 1) yell at them and 2) find another host. – ThatGraemeGuy Aug 28 '13 at 11:21

2 Answers2

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A dedicated server with local disks is the only answer if you want to have guaranteed, consistent I/O response times. Even a dedicated physical server (not even to mention a virtual one) connected to a SAN can be dog-slow if the SAN is way too overloaded.

So, better to choose your next host wisely! No amount of software tuning can do if the physical hardware is severely lagging.

Janne Pikkarainen
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  • Thanks Janne, you have any reputable host that you can recommend? Ya'know, the one that wont' make its VPS subscriber to wait for 10 seconds for an INSERT query to complete – Graviton Aug 28 '13 at 09:46
  • Well that depends on where are you from, what kind of traffic you except, what kind of database size you except, details like that :) Amazon? – Janne Pikkarainen Aug 28 '13 at 09:47
  • We are hosting an internal vtiger CRM app for our own use ( about 20 users at most), so it's not Google/Amazon kind of massive websites. And we won't have more than 1K traffic per month, of course :) – Graviton Aug 28 '13 at 09:49
  • .... and from the USA? – Janne Pikkarainen Aug 28 '13 at 09:53
  • Nope, not from USA, mostly in South East Asia region – Graviton Aug 28 '13 at 11:12
  • `Oppan Gan....` sorry, you should then research for your area and find a host who truly can serve you. I have no expertise for your area but since areas like SK seem to lead to technology, I would guess you have plenty of choices. – Janne Pikkarainen Aug 28 '13 at 11:19
  • Janne, I think the bottleneck is in database and server response time, as for location wise, it is not significant, so I won't mind a US based hosting provider – Graviton Aug 28 '13 at 11:31
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The straight answer is yes. The machine has a set of discs that have a specific IO budget. That is shared between all VPS. Same as with processors.

THis is a know nissue of all shared ressources - before virtualization it was a known issue with SAN's and not too well defined specs, so a database ended up on shared discs in a SAN. Same issue: inconsistent IO´because the IO budget is not "hard" but your allocation depends on other machines.

10 seconds is horrific, though. Seriously horrific.

Cloud is the same. You want deterministic capabilities you need to have either your own hardware (not necessarily OWNED) or a shared host that has the ability to allocate budgets (for example for IO) that you get. This will cost.

But seriously, again, 10 secnds is TERRIBLE. Try a less cheap host.

TomTom
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  • `Try a less cheap host`-- but my VPS costs USD 55 per month, this although is not too expensive, but nonetheless doesn't entail me to suffer a 10 second delay, right? – Graviton Aug 28 '13 at 11:13
  • Absolutely. 55 USD - is definitely not on the cheap side. Sorry for assuming that. 10 seconds OTOH is nearly comical - I have a problem seeing that outside a totally overloaded disc subsystem. A 1 secnod delay would be bad. – TomTom Aug 28 '13 at 11:58