Sorry about the caps.  My recent threads have detailed my need for a robust server that can handle periods of heavy use.  I am currently running LS5 on a cloud hosted server with 2 vcpu and 8Gb ram all SSD.  HOWEVER -- instead of spreading sessions over two weeks, the client has scheduled about 16,000 people to do their survey over two days, many in groups starting at the same time.  My server hit a load of 5 with about 500 people hitting the server in a 5 minute window when working with a subgroup.  After seeing that I upped the server to 8 vCPU, 16GB and also learned a lot about php-fpm and flipping it up to 275 child processes but hey.   I know that it is all about the session files
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[please note my restraint in using all caps]
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I have written LS sales, but I  know it is getting late in Europe.  Can anyone who has used the cloud hosted LS service tell me about my key questions?

1.  Can I migrate over using export+import
2.  Do they have US based hosts
3.  Does the cloud service scale to meet that many requests at once, I can't find specs for their servers
4.  How much per response after reaching 10000 annual.

This will be an OVERNIGHT PROJECT (sorry) but right now I feel like I am facing two unknown scenarios.  Any experiences that you can relate would be appreciated beyond words. 
Chris
 

A couple of your questions you can actually already find in the FAQs:

1. Can I migrate over using export+import

I think the survey generally should be no problem, either via LSS (just the survey structure), or LSA (includes also previous responses, etc.). Now, you need to watch out and check with Limesurvey GmbH if you can get a LS 5 server, because I think they are currently moving from LS3 to LS5 on their servers. I guess new installations will be probably all LS5 now, but better check this with them. Why? Due to some changes in the database structure you can not (afaik) import LSS files exported from LS5 into LS3 (from LS3 to LS5 is no problem).

2. Do they have US based hosts

www.limesurvey.org/support/faq/39-data-p...y-data-hosted-stored

So it seems like there is an option in the US.

3. Does the cloud service scale to meet that many requests at once, I can't find specs for their servers

I think only the Limesurvey GmbH Support will be able to respond. Most of us here run Limesurvey CE and have no experience with how the SaaS offering performs on high loads.

4. How much per response after reaching 10000 annual.

I am sure you can get a quote for more than 10.000 responses. But also keep an eye on how responses are counted!

www.limesurvey.org/support/faq/37-limesu...re-responses-counted

A survey that is completed over 50% but not finished seems to be counted as 0,5 of a response, so depending on the response rate and the response behaviour, you might run into your limit earlier than you expect.

Generally, dropouts mostly happen during the first couple of questions, but if you have a very long survey people might drop out on a later stage as well. So just keep this in mind.

3278142 wrote:

instead of spreading sessions over two weeks, the client has scheduled about 16,000 people to do their survey over two days, many in groups starting at the same time.
 

Is the survey with open invitation links? Or are you using tokens?  When you have a survey hitting the limit of the server people start to reload and reaccess a survey. Without token you have no limit nore a way to check for doubleentries.

I wonder why you expect a high response quote from a crowd of 16000 people? Are these people forced to do the survey? As long as the files sessions have enough space on the SSD, the session files are fine.

The RAM usage of a PHP and Apache process  (if you still use Apache) are important to know. That way you can decide if RAM should go up or the amount of processes should be limited.Max Children = (Total Ram - (Used Ram + Buffer)) / (Memory per PHP process)
275 = 16384 MB - (Used Ram of OS+Applications+Buffer) / Memory per PHP process)
The memory usage of each PHP process depends on how many extensions are complied into PHP.

A similar calculation can be done with the Apache processes and the database.

An bottleneck often overlooked is the bandwidth the server has. 100MBit/s or 1000MBit/s can be a difference.
A survey is normally not big in terms of data volume per page. But if you have picture,audio and video files used in the survey, the bandwidth can be the limiting factor on how many people can request from the server at once.
E.g. 100 MBit/s is 13MB/s or 750MB/m.

If you survey is running fine and you have to start in the next 24h I would recommend to check the memory usage and ensure that the max children of php-fpm will leave enough memory for OS,Apache and database.

Before moving to LS cloud, check the free trial to move your themes and possible workarounds there.









 

With such need : best is to contact LimeSurvey GMBH directly.

With such need : best is to contact LimeSurvey GMBH directly.

Which is what 3278142 did...

I have written LS sales, but I know it is getting late in Europe.

I guess he/she "panicked" a little bit because of the urgency and the fact that in Germany probably no one will answer support/sales emails at this time of the day.

holch wrote:

With such need : best is to contact LimeSurvey GMBH directly.

Which is what 3278142 did...

 

Yes : but only LimeSurey GMBH can really answer …