[moin-user] MoinMoin very slow

[Volker Wysk]

Am Donnerstag, 2. November 2017, 00:16:05 CET schrieb Paul Boddie:
> On Wednesday 1. November 2017 23.44.28 Volker Wysk wrote:
> > 
> > This looks like this:
> > 
> > Page.execute = 20.668s
> > i18n_init = 0.299s
> > init = 0.370s
> > loadLanguage = 0.115s
> > load_multi_cfg = 0.274s
> > run = 41.985s
> > send_page = 41.809s
> > send_page_content = 41.156s
> > send_page_content|1 = 20.578s
> > send_page|1 = 20.578s
> > total = 42.354s
> 
> So, working through this without any recent knowledge or experience myself, I 
> see that the MoinMoin.Page.Page.send_page_content method is the thing using 
> all the time. It obtains a parser and then either gets a cached version of the 
> page or formats a new version.
> 
> Is there anything special about the page? Anything like macros being used, for 
> instance.

I'm using some  <<BR>> macros, and a "#!highlight" parser. Also using 
<<TableOfContents>>. Disabling the TOC and the parser didn't speed things up.


> > > Other than that, some kind of idea of the environment Moin is operating
> > > in might be useful...
> > 
> > Kubuntu 16.04, Apache2, ...
> > 
> > > Publicly accessible or inaccessible?
> > 
> > inaccessible, one user only
> > 
> > > Lots of processes on the machine or only a few?
> > 
> > This process runs alle the time with 100% CPU:
> > 
> >   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
> >  8509 www-data  20   0  106144  49460   9340 R 100.0  0.6   0:04.94 python
> 
> This indicates that it is presumably quite busy and not necessarily waiting 
> for input/output, so the nameserver suggestion is probably uninteresting.

I've tried vwysk.now-dns.net (my dynamic DNS-Name), localhost and 
127.0.0.1. No luck. All slow.

> 
> > > Local or network filesystem?
> > 
> > Local.
> > 
> > > Nameserver usage: are the Web server and Moin doing reverse DNS lookups?
> > 
> > How to find this out?
> 
> I suppose the easiest way is to just look at your Apache and Moin logs and see 
> if you have numeric IP addresses or ones with actual names. But I doubt that 
> this would cause the time to be consumed in send_page_content, so we can 
> perhaps rule this out as a cause.
> 
> > > Try show_timings first of all, though.
> > 
> > See above.
> > 
> > And: It runs much faster for smaller pages.
> 
> I do wonder about "send_page_content|1" which might well be a recursive call 
> generating a subpage, perhaps for a table of contents. The way that the 
> combined time is approximately double the individual times might suggest that 
> the cache isn't working properly. But 20s page generation times are not 
> exactly normal, either.

A special cache for MoinMoin? How do you configure it? I might not have 
installed it, because I thought I don't need it.

 
> It's been a long time since I troubleshooted a Moin performance problem like 
> this, and then I think it was probably related to the low-performance, non-
> Xapian search function, not page loading.

Regards,
Volker