Shared site, poor database performance acceptable?


#1

I wrote to Dreamhost support asking about the poor performance I’m getting from my database driven sites, that are not even under load yet. I am still testing them, yet the performance can be downright pathetic. The response I got left me scratching my head. Just because I am on a shared server, does not mean I should expect or accept poor database performance. I understand a very occasional spike, but these slowdowns are for extended periods of time and occur every single day.

What has your experience been with these types of issues? I am hosted on Zuma. My message and their reply follows:

I WROTE:
I am finding the performance of the server my sites are hosted on to be quite spotty. My
two main sites are database driven using osCommerce and PHPBB2. Both of these sites
are under minimal load, yet can be super fast or super SLOW running the same tasks,
just different times of the day.

I’d ask that you please investigate and act accordingly. My customer wants to know why
the site “slowed down since moving to the new host”, damn customers! :slight_smile:

DREAMHOST RESPONDS:
I see no problems with the servers your site is on. Since this is on a
shared hosting server, it is very possible that there are just very high
loads on mysql servers/web servers during the day. That could be what is
causing slower than normal load times, but I see no reported problems
with any of the servers you are on. Let me know if there is anything else
I can help you with.

Thanks!
Jordan


#2

I’m having the same problem. I’ve had the page time out a few times this evening.

I was going to use PostNuke, but half the day it is so slow it is useless.

I haven’t sent an email to support yet.


#3

Are you hosted on Zuma? If you aren’t sure, check the first couple emails they sent you. You should see the host name in there as part of the temporary address they give you until your DNS is in place.

What do you think about that response? If one of my support engineers responded to a customer like that, they would get one warning - the next time they would be canned.

Dreamhost is awesome in terms of features and their control panel. Their support is pretty good, not fast, but at least you can rely on them to reply within 24-hours - better than many others. However, this attitude of “you are shared hosting customer so deal with the overloaded server”, is garbage.


#4

Okay, well here’s the next reply from DH. He wants specific information, that’s fine I can understand that. It’s a bit of a punt seeing how he already told me it’s likely the database server is the culprit. Still I’ll provide the information, and but based on how this has gone so far - I am not expecting to be satisfied when this is over. If there are other people here dissatisfied with the performance of their sites, please post.

Is Jordan the only support person they have? Just curious…

FROM DH SUPPORT (Jordan):
Hello,

Please give me a specific example of what pages are loading slowy, I do
not see any pages on your website except an under construction message. I
will need to know specific information, what databases are acting slowly,
what type of internet connection are you testing from. I will need
traceroutes to our webserver during the time you are experiencing
slowness. There are many reasons why a site could be loading slowly, not
just server load problems. For info on doing a traceroute please look at
this kbase article…
https://panel.dreamhost.com/kbase/index.cgi?area=281&keyword=traceroute

Thanks!
Jordan


#5

Yes, database servers have been getting slower and slower over the past several months, I have my eye on this recent and very real issue as well, fwiw.

[color=#0000CC]jason[/color]


#6

Is it a consistent timeout for new connections (~ 56 seconds)? If so, it may be due to DNS resolution problems…


#7

I see wild variations as well, sometimes during the same session (say, a half hour reading, posting and administrating on a forum). About the time I’m ready to shoot myself from the long lags and painful page loads I suddenly get zippy performance and I think, hot-dang, this is sweet! Accessing from work or home, no matter. It can happen day or night, although possibly performance is somewhat more likely to be OK at night. I never really associated it with db servers until I switched forum apps and was trying to get a feel for relative performance. (Impossible really; they ended up being on different db servers, and BOTH had episodes of terrible response times.) When I have bad performance on the forum I frequently load our main site (no db involved) to see if it’s my ISP or internet congestion or something universally icky (I’m not savvy enough to run actual analytical tools) and performance is almost always excellent on the main site.


#8

Like haggis said, spotty. Certainly feels like a useage issue to me. As more and more free, open apps with easy cheesy installers hit the shelves, more people utilize MySQL, performance goes down.

I recall reading in the kbase when I was researching something or other, probably persistent processes or the like, Dreamhost’s primary focus was “serving web pages”. That was used as the reason that you don’t allow such and such a thing, or don’t support it or whatever. That’s always been in the back of my mind when I look at performance issues here and by golly, it’s true. HTML pages load like lightning, always.

But don’t you think straight html sites are going by the wayside in favor of those served from a db?

I’d be interested to hear what you guys are doing to address this issue, specifically: is the plan to let the MySQL performance continue on a downward spiral or are you actively looking at this issue and have plans to bring it back to it’s previous performanc levels (pre-proliferation of phpBB and MT type apps)?

thanks

[color=#0000CC]jason[/color]


#9

It isn’t a DNS issue.

I am currently using a small application called phpHoo, which is a directory type thing. I have about 150 links in it currently. Previously I was using WebLinks from PostNuke. The performance in the evening has been so bad that I was unable to load the links from PostNuke. I would click on a category and the browser would continue waiting for a response. This is with different browsers, different computers running Windows and Linux.

I ended up dumping the data from phpmyadmin and after some editing, loading it into the database for phpHoo. Now when I am adding or editing links, there is often a delay of 3-5 seconds in the late afternoon and evening, with several timeouts in the later part of the evening. At times it will perform like it should, but this is seldom the case in the evening.

This appears as if someone is running something that is hammering the server, and if I click on a link at the precise moment the server isn’t being hammered, it works like it should.

As for the apps not being efficient, I imagine that is a possibility, but there are a lot of sites with PostNuke and phpHoo that respond instantly upon clicking a link.


#10

I’m fairly certain it is.


#11

Is that good news or bad news?


#12

On who’s end?


#13

On ours. It’s a known issue and is being worked on.


#14

I’m currently having trouble bringing up DB driven sites, about 30 seconds to load pages that make DB queries. HTML/PHP pages that make no queries are loading fine.

It’s this DNS issue still an issue or is this something else?

[color=#0000CC]jason[/color]


#15

[quote]It’s this DNS issue still an issue or is this something else?

[/quote]

As far as I know, the DNS issues usually added - at most - a few seconds to queries. The easiest way to verify if this is a DNS issue is to change the hostname reference in your script to the IP address instead. If it’s suddenly faster, it’s probably DNS.

There are a whole host of other potential issues, though. Is it possible that you have some very slow queries that could be optimized? Have you indexed your tables? Do extremely simple queries run slow as well? There are a million things that can impact database performance, often making fixing slow scripts a lot of work. :>

As an aside: I’m not sure if the DNS issue is even still a problem or not, since that’s not in my realm. Will?

  • Jeff @ DreamHost
  • DH Discussion Forum Admin

#16

The problems are still being worked on, but we have already made some changes that seem to have helped a lot.


#17

Well no, see, they’re like lightening this evening, the very same pages/queries. One was only pulling 5 or 6 fields from 1 table, the other I forget but it is pulling a hella buncha queries, 40-60 maybe, crazy page. Both behaved the same, about 25-30 seconds of nothing, then the page loads; tonight they’re both responding fine.

It still seems to be having something to do with useage to me, the busy times of day, it’s killin me

[color=#0000CC]jason[/color]


#18

[quote]Well no, see, they’re like lightening this evening, the very same
pages/queries. One was only pulling 5 or 6 fields from 1 table, the
other I forget but it is pulling a hella buncha queries, 40-60
maybe, crazy page. Both behaved the same, about 25-30 seconds
of nothing, then the page loads; tonight they’re both responding
fine.

[/quote]

I see. This would usually indicate that the database structure is optimized okay, though if your site is receiving a lot of accesses during that time it could impact it still (though again, 25-30 seconds is far beyond just ‘slow’ or ‘a little bogged down’ in my opinion).

[quote]It still seems to be having something to do with useage to me,
the busy times of day, it’s killin me

[/quote]

Do you have any idea on when this tends to happen? Certain times of the day, for example? Weekends vs. Weekdays?

Also, have you tried switching to an IP for your connections and seeing if that makes a difference?

  • Jeff @ DreamHost
  • DH Discussion Forum Admin

#19

I actually felt really bad about saying that after I posted it cuz I tried to recall times and could not. If it continues to be a problem I’ll log it.

I’ll try it and report back, meant to do this yesterday but never got the chance.

Thanks for the help.

[color=#0000CC]jason[/color]


#20

I tried the IP and it is still unbearably slow.

I originally gave up on PostNuke because I thought it might be PostNuke. Every CMS I’ve tried has been incredibly slow. This is driving me nuts. It is way too slow.