I got this from my host...and have subsequently removed Redmystic from my site.  I hope this can help any future development:

Your account "mysite.com" on shared server sub.servername.com  is running multiple instances of scripts and causing major problem for the entire server.  We have been monitoring this for the last couple of hours. After carefully watching the server hardware consumption at the time when the load increases and server performance decreases, we have identified that your account is the one causing problems on the server.

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myuser  3266  0.4  0.4 178776 19056 ?        D    02:29   0:00 /usr/bin/php /home/myuser/public_html/index.php
myuser  13082  0.2  0.3 209528 14884 ?        D    01:40   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  14665  0.2  0.3 208756 13656 ?        D    01:44   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  14700  0.2  0.3 209532 13652 ?        D    01:44   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  14824  0.2  0.2 209532 12048 ?        D    01:45   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  15211  0.1  0.3 200668 14932 ?        D    01:45   0:03 /usr/bin/php /home/myuser/public_html/index.php
myuser  15748  0.2  0.3 208732 13360 ?        D    01:47   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  15883  0.2  0.6 188988 27240 ?        D    01:47   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  15901  0.2  0.3 209792 14084 ?        D    01:47   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  16591  0.2  0.3 208760 14036 ?        D    01:49   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  17039  0.1  0.3 200928 15872 ?        D    01:50   0:04 /usr/bin/php /home/myuser/public_html/index.php
myuser  17713  0.3  0.3 209784 14408 ?        D    01:52   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  17804  0.2  0.3 209788 12688 ?        D    01:53   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  17915  0.2  0.3 209784 14932 ?        D    01:53   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  18033  0.2  0.6 209780 25396 ?        D    01:53   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18445  0.2  0.4 209784 17296 ?        D    01:54   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  18670  0.3  0.3 209272 12184 ?        D    01:55   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  18682  0.3  0.3 209784 12808 ?        D    01:55   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18713  0.3  0.3 209020 14048 ?        D    01:55   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18793  0.3  0.3 209256 13076 ?        D    01:55   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18797  0.3  0.3 208740 13588 ?        D    01:55   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  18799  0.1  0.3 211600 12680 ?        D    01:55   0:03 /usr/bin/php /home/myuser/public_html/index.php
myuser  18805  0.2  0.3 200924 13116 ?        D    01:55   0:04 /usr/bin/php /home/myuser/public_html/index.php
myuser  18810  0.3  0.3 208744 13508 ?        D    01:56   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18813  0.1  0.3 200932 14104 ?        D    01:56   0:03 /usr/bin/php /home/myuser/public_html/index.php
myuser  18834  0.3  0.3 208748 13248 ?        D    01:56   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  18859  0.2  0.3 200928 13752 ?        D    01:56   0:04 /usr/bin/php /home/myuser/public_html/index.php
myuser  18883  0.3  0.3 209780 13500 ?        D    01:56   0:08 /usr/bin/php /home/myuser/public_html/index.php
myuser  18924  0.1  0.2 200928 11988 ?        D    01:56   0:03 /usr/bin/php /home/myuser/public_html/index.php
myuser  18944  0.3  0.3 209248 12152 ?        D    01:56   0:07 /usr/bin/php /home/myuser/public_html/index.php
myuser  18979  0.2  0.3 209788 13788 ?        D    01:56   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  19136  0.3  0.3 209788 12424 ?        D    01:57   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  19304  0.3  0.2 209800 11764 ?        D    01:57   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  19410  0.1  0.3 200932 13164 ?        D    01:58   0:03 /usr/bin/php /home/myuser/public_html/index.php
myuser  20753  0.3  0.3 209784 12368 ?        D    02:00   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  20982  0.3  0.3 209780 13640 ?        D    02:02   0:05 /usr/bin/php /home/myuser/public_html/index.php
myuser  21212  0.4  0.3 209400 13108 ?        D    02:04   0:06 /usr/bin/php /home/myuser/public_html/index.php
myuser  21708  0.3  0.3 210040 13572 ?        D    02:05   0:05 /usr/bin/php /home/myuser/public_html/index.php
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 4576 myuser  16   0  194m  38m 6696 S 67.1  1.0   0:02.02 /usr/bin/php /home/myuser/public_html/index.php
 4612 myuser  16   0  194m  38m 6696 R 91.5  1.0   0:01.50 /usr/bin/php /home/myuser/public_html/index.php
 4669 myuser  16   0  194m  38m 6696 R 49.8  1.0   0:01.50 /usr/bin/php /home/myuser/public_html/index.php
 4677 myuser  17   0  204m  47m 7220 S 94.4  1.2   0:05.37 /usr/bin/php /home/myuser/public_html/index.php
 4706 myuser  16   0  193m  38m 6716 R 71.5  1.0   0:02.15 /usr/bin/php /home/myuser/public_html/index.php
 4697 myuser  16   0  194m  38m 6716 R 65.1  1.0   0:02.10 /usr/bin/php /home/myuser/public_html/index.php
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We had no choice but to disable web access of your account to stabilize the server. Please optimize your code/script to avoid these heavy resource consuming apache usage or upgrade this account to semidedicated  plans. You can find our semidedicated plans here:

http://www.dedicatedserver.com

Please do not reply to this email, rather login to your client area at dedicated.com and update the support ticket ####### to follow up.

Kindly let us know if there is anything else we can do for you.

Regards,
Technical Support Representative

Hi,

Redmystic itself wouldn't of caused this. I suspect it's search engines crawling your site after the sitemaps were sent to them. The search bots typically spider with many instances so it'll look like 50 or so users are hitting your site simultaneously. Couple that with the large number of products you have on a shared hosting and yeah I can see how this might upset  your provider.

I know you've disabled redmystic but here are few thoughts that could help:

1. Disable the sitemap generation part of the component. It will no longer notify the search engines. You should also delete the sitemaps located in /components/com_redmystic/sitemaps

2. There are some spidering adjustments that can be made in Google's webmaster tools. That may help

3. As your provider mentioned, upgrading to a virtual dedicated will help tremendously. This link can help http://redmystic.com/index.php?option=com_content&view=article&id=69:redmystic-validated-hosting-&catid=10:faq-answers&Itemid=18

Cheers,

--Garry

One thing I just thought of where redmystic could cause high memory use is in the compression process. Basically the component will zip up the feed file and sitemaps to reduce  bandwidth. If your site has more than a thousand products then it's critical to use zipArchive instead of Joomla's JARchive. These settings can be found in the redmystic configuration. zipArchive is significantly more efficient. Here's an example of a test I performed recently on a test server:

Product Feed of 100,000 products.

Using zipArchive the memory consumption never exceeded 9MB.

Using JArchive I was not able to complete the compression even with 500MB !

The downside of zipArchive is that you must be using php 5.2 while JArchive is pretty much universally available.

Cheers,

Garry