AWS EC2 Ubuntu Tomcat PostgreSQL

vmassol · April 14, 2018, 10:58pm

Thanks a lot for updating the pages. I’ve rolled-back your changes for the moment though for the following reasons:

The memory requirements should be only on http://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Performances/#HMemory and not on http://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Installation/#HHardwareandSoftwarerequirements to not spread the info in several places
I don’t understand why you think the OS needs 2GB of RAM when we say that we only require 1MB of JVM memory to run XWiki. This means you assume that whatever the OS, we need to have 1GB of RAM for the OS. Can you substantiate that and let us know why we couldn’t run XWiki on OSes with smaller memory needs for example?
In any case we don’t care what memory you put for your OS. All that XWiki cares about is that it gets 1MB of RAM in the JVM. Whether you run it on rasberry PI or on some supercomputer with tons of memory doesn’t change that.

Thanks.

PS: I’ll be happy to put back your change when I better understand your point. Thx!

rbr · April 16, 2018, 9:15am

I guess you are right, it’s just a bit too generic to ask for 2GiB system memory minimum requirement.
What I wanted to provide was some kind of a “if you start with this (2GiB) you should be good in most cases” value. My thoughts are like this: If you start with xwiki you will most likely do a standalone installation, with database and servlet container on one host. If you really have a small memory VM (let’s say 1GiB or 1.5GiB) your machine may start swapping or with no swap run into an OOM exception while starting up or during DW. This may be enough to no longer consider xwiki as an option.
On the other hand if people have a guideline and ignore it, for whatever reason, they usually know that they have to expect reduced performance at least.
The guys I know, including me, that install software on a pi hope for good performance but actually don’t expect it, because the specs are on the low end.

And yes you may get away with around 1GiB of sytem memory, with the recommended settings (-Xmx1024m). My playground environment has 2GiB and around 1000MiB RAM available. But this is an one user, ultra low traffic test installation.

While I really like xwiki and are often surprised about how well it performs I guess you are a bit off with it’s memory requirements

With all that said, I’m still in favour of providing this kind of guideline.

rbr

vmassol · April 16, 2018, 11:40am

Not sure about that

On https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Performances/#HMemory it says we use -Xmx1600m for xwiki.org which has several thousands and is very heavy in term of view usage. So a default of -Xmx1024m for small installs and -Xmx2048m for large installs seems about right to me.

rbr · April 16, 2018, 12:06pm

Hi @vmassol,

I’m really sorry, it was meant as a joke, because what I pointed to was that you talked about 1MB. Not 1024MB. Not 1GB.
And yes I know that this was typo, still I thought it was good enough for an “a bit off” joke.
And no, otherwise I do not question at all the memory usage you provided.

rbr

vmassol · April 16, 2018, 12:28pm

haha didn’t notice my typo