Mailing List Archive

On Nov 28, 2004, at 8:46 AM, Plamen Gradinarov wrote:
> However I try to start any file from the maintenance, say,
> refreshLinks or rebuildSearchIndex, the result is invariably one and
> the same:
> "Sorry! The wiki is experiencing some technical difficulties, and
> cannot contact the database server."

Can you confirm that the database username and password in
AdminSettings.php are correct, and that you can use them to connect to
the server with the command-line 'mysql' client? Can you confirm that
you spelled $wgDBadminuser and $wgDBadminpassword correctly, with that
exact case usage?

> Even the proposed workaround for rebuilding the links is not working.

What workaround is that, and where is it proposed?

> First it returns
>
> ERROR 2006: MySQL server has gone away
> No connection. Trying to reconnect...

Check mysql's error log; MySQL may be crashing or having other problems.

-- brion vibber (brion @ pobox.com)

> Can you confirm that the database username and password in
AdminSettings.php are correct?

Thank you very much, Brion, you are very helpful! Of course, it was my
fault, there were my wikiadmin logins in the AdminSettings.php, not the
wikiDB ones. Now the real count started by 50 and seems to take several
hours (probably more than 36 at the present rate).

The workaround (I'm afraid I took it for a standalone replacement of the
entire rebuild problem, while it should be applied only if the commandline
solution works but still returns 0 articles) is found here:
http://meta.wikimedia.org/wiki/Documentation:Administration
starting with: "To rebuild the article count manually"

Thanks again,
Plamen

BTW, how much time and space will take the creation of a SearchIndex for the
last dump of the English Wiki? Now the CPU load is about 3.60 (Dual Xeon 2.8
HT). Probably it will be less with an additional 1 GB RAM... Are there any
hardware requirements for running, say, an English cur replica of Wikimedia?

On Nov 29, 2004, at 1:06 AM, Plamen Gradinarov wrote:
>> Can you confirm that the database username and password in
> AdminSettings.php are correct?
>
> Thank you very much, Brion, you are very helpful! Of course, it was my
> fault, there were my wikiadmin logins in the AdminSettings.php, not the
> wikiDB ones. Now the real count started by 50 and seems to take several
> hours (probably more than 36 at the present rate).

Building the link tables takes a long time as it requires parsing and
rendering every page in the database to determine which links are used.

If you're just pulling the Wikipedia database dumps, you might consider
importing the links table backups that we provide with the dumps. At
http://download.wikimedia.org/archives/en/ you'll see
en_links_table.sql.gz, en_brokenlinks_table.sql.gz, etc.

> The workaround (I'm afraid I took it for a standalone replacement of
> the
> entire rebuild problem, while it should be applied only if the
> commandline
> solution works but still returns 0 articles) is found here:
> http://meta.wikimedia.org/wiki/Documentation:Administration
> starting with: "To rebuild the article count manually"

This explains how to set the article count; it's not related to
rebuilding the link tables at all, but is a separate operation. This
doesn't take _too_ long, but again if you want to skip it you can pull
eg en_site_stats_table.sql.gz.

> BTW, how much time and space will take the creation of a SearchIndex
> for the
> last dump of the English Wiki?

The searchindex table for en.wikipedia.org and its fulltext index
together are about 5.2GB on our server. Generating the search index
should go much faster than building the link tables, as the entries are
only lightly processed, but may still take a few hours for that large a
database depending on your system's speed and other system load while
it's running. We don't currently make public backups of the search
index table due to the size and the relative ease of regenerating it.

> Now the CPU load is about 3.60 (Dual Xeon 2.8
> HT). Probably it will be less with an additional 1 GB RAM... Are there
> any
> hardware requirements for running, say, an English cur replica of
> Wikimedia?

Requirements will depend mainly on usage. You should probably install a
PHP optimizer such as Turck MMCache (a very easy way to make any PHP
apps run faster), and if load is high consider the other caching
options (file cache mode, squid reverse proxy with squid mode turned
on, memcached+parser cache).

-- brion vibber (brion @ pobox.com)