Sharepoint Crawl

As a note, i've noticed the Fast Search Farm event log stopped recording event logs at the same time as the last incremental crawl finished.
I've not seen any SP stopped or indication of any element not running.

Reset the crawl index:
http://technet.microsoft.com/en-us/library/gg702114.aspx

Might take a while.

is just that it will erase all existing indexing and will not allow users to search until full crawls have been run on all content sources.
If i take that way it will be over the weekend,

Yes it will remove all content and start from scratch.  
If you incremental searches are not running, then none of the latest documents/info put into Sharepoint will be returned in searches until you do this, so you have to way up the danger of leaving it with missing information being returned from the search compared with the danger of having no search function until it completes.

You might be able to backup and restore teh search database but I've never done it.

ON another note....mind commenting on this thread?

https://www.experts-exchange.com/questions/27586468/Real-World-FAST-Search-for-SharePoint.html

I haven't reset the index.
Looking at both, the front end SharePoint server and the backend Fast search server's event logs i have found many warning on the Fast server.
The message being:
"Could not send batch to content distributor, will retry automatically. Reason given: create_sessioin() failed: unable to create sessions with master contentdistributor"

I'm afraid resetting the index will not fix the problem, will not allow the users to do any search until a new full search is done and this may not happen if there are this subtle problems with the contentdistributor.

I used the stsadm tool to list and delete (their links) the content databases that were not synchronized.

I also found the contentdistributor.cfg file on my \FastSearch\etc folder and the hostname:port (hostname:13390) there was different from the install.txt entry (hostname:13391), i changed the contentdistributor file's entry to match the install.txt but the warning still there,

I don't want to reset until i know it's going to crawl, otherwise i'll be in a worse situation.

Any ideas?

Also to mention that i found indexing is working good:

indexerinfo status > 
<indexer hostname="hostname" port="13050" cluster="webcluster" column
="0" row="0" factory_type="filehash" preferred_master="no" connected_feeds="0" s
tatus="running ok" heartbeat="Running" exclusion_interval="60" time_since_last_i
ndex="0">
<documents size="0.000000" total="1154525" indexed="1154525" not_indexed="0"/>

I found the root of the problem.
THe certificate had expired, exactly dates when the crawling started to 'hung'
Im in the process of recreating new one now

I've generated a new certificate on the FAST server using the .\replacedefault... script and the -generatenewcertificate switch.
And then back on the front server, .\replacedefaultcertificate with the thumbpint of the certificate i created and exported from the FAST server.
It all looked like the cert had been created and installed on both servers but somehow i don't think they're working properly.
Running Ping-SPEnterpriseSearchContentService -Hostname hostname:13391 it gives a list of three certificates:
ForefrontIdentityManager
FASTSearchCert (the one i created and exported)
WMSvc-Hostname

All three show a connectionsuccess = false.

When i run (on the front server): .\securefastsearchconnector.ps1 -certthumbprint "the fastsearchcert thumbprint" -ssaName "Fast Search Service" -username  .....

it says my FAST search connector has beeen setup to use certificate, restarting osearch 14.

It hungs for a while and then complains:
"Connection to contentdistributor hostname:13391 could not be validated.

So i keep seeing the errors on the applicaton event log:
"Failed to connect to hostname:13391. Failed to initialize session with document engine: Unable to resolve contentdistributor"

And the crawling still stalled