First, you should configure mnoGoSearch. Indexer configuration is covered mostly by indexer.conf-dist file. You can find it in etc directory of mnoGoSearch distribution. You may take a look at other *.conf samples in doc/samples directory.
To set up indexer.conf file, cd to mnoGoSearch installation /etc directory, copy indexer.conf-dist to indexer.conf and edit it.
To configure search front-ends (search.cgi and/or search.php3, or other), you should edit search.htm file in /etc directory of mnoGoSearch installation. See Templates section for detailed description.
Just run indexer once a week (a day, an hour ...) to find the latest modifications in your web sites. You may also insert indexer into your crontab job.
indexer with built-in database support can't do reindexing and indexes the whole site every time it is started.
By default, indexer being called without any command line arguments reindex only expired documents. You can change expiration period with Period indexer.conf command. If you want to reindex all documents irrelevant if those are expired or not, use -a option. indexer will mark all documents as expired at startup.
Retrieving documents, indexer sends If-Modified-Since HTTP header for documents that are already stored in database. When indexer gets next document it calculates document's checksum. If checksum is the same with old checksum stored in database, it will not parse document again. indexer -m command line option prevents indexer from sending If-Modified-Since headers and make it parse document even if checksum is the same. It is useful for example when you have changed your Allow/Disallow rules in indexer.conf and it is required to add new pages that was disallowed earlier.
If mnoGoSearch retrieves URL with redirect HTTP 301,302,303 status it will index URL given in Location: field of HTTP-header instead.
indexer has -t, -u, -s options to limit action to only a part of the database. -t corresponds 'Tag' limitation, -u is a URL substring limitation (SQL LIKE wildcards). -s limits URLs with given HTTP status. All limit options in the same group are ORed and in the different groups are ANDed. mnoGoSearch with built-in database dos not support subsection control.
To clear the whole database, use 'indexer -C'. You may also delete only the part of database by using -t,-u,-s subsection control options.
If you run indexer -S, it will show database statistics, including count of total and expired documents of each status. -t, -u, -s filters are usable in this mode too.
The meaning of status is:
0 - new (not indexed yet) URL
If status is not 0, then it is HTTP response code, some of the HTTP codes are:
200 - "OK" (url is successfully indexed)
301 - "Moved Permanently" (redirect to another URL)
302 - "Moved Temporarily" (redirect to another URL)
303 - "See Other" (redirect to another URL)
304 - "Not modified" (url has not been modified since last indexing)
401 - "Authorization required" (use login/password for given URL)
403 - "Forbidden" (you have no access to this URL(s))
404 - "Not found" (there were references to URLs that do not exist)
500 - "Internal Server Error" (error in cgi, etc)
503 - "Service Unavailable" (host is down, connection timed out)
504 - "Gateway Timeout" (read timeout when retrieving document)
HTTP 401 means that this URL is password protected. You can use AuthBasic command in indexer.conf to set login:password for this URL(s).
HTTP 404 means that you have incorrect reference in one of your document (reference to resource that does not exist).
Take a look on HTTP specific documentation for further explanation of different HTTP status codes.
Being started with -I command line argument, indexer displays URL and it's referrer pairs. It is very useful to find bad links on your site. Don't forget to use DeleteBad no indexer.conf command for this mode. You may use subsection control options -t,-u,-s in this mode. For example, indexer -I -s 404 will display all 'Not found' URLs with referrers where links to those bad documents are found. Setting relevant indexer.conf commands and command line options you may use mnoGoSearch special for site validation purposes.
MySQL and PostgreSQL users may run several indexers simultaneously with the same indexer.conf file. We have successfully tested 30 simultaneous indexers with MySQL database. Indexer uses MySQL and PostgreSQL locking mechanism to avoid double indexing of the same URL by different indexer's copies. Parallel indexing in the same database is not implemented for other back-ends yet. You may use multi-threaded version of indexer with any SQL back-end though which does support several simultaneous connections. Multi-threaded indexer version uses own locking mechanism.
It is not recommended to use the same database with different indexer.conf files! First process could add something but second could delete it, and it may never stop.
On the other hand, you may run several indexer processes with different databases with ANY supported SQL back-end.