Transactional Replication Status Checker.

For simple monitoring we can use the following queries to get the latest status of transaction replication.
(It may required little tweak as per requirements)

-- Transactional Replication Status Script
use distribution
go

select d.Publication, d.Publisher_db, a.Agent_id, d.Name,
case a.Runstatus
when 1 then 'Start -- Ok'
when 2 then 'Succeed -- Critical'
when 3 then 'In progress -- Ok'
when 4 then 'Idle -- Ok'
when 5 then 'Retry -- Critical'
when 6 then 'Fail -- Critical'
end Replication_Status
, a.Time, a.Comments, isnull(c.error_text,'') Error_Text
from dbo.MSdistribution_History a
join
(
select agent_id, max(time) Max_Time
from dbo.MSdistribution_history
group by agent_id
) b on b.agent_id = a.agent_id and b.max_Time = a.time
left outer join dbo.MSrepl_errors c on c.id = a.error_id
join dbo.MSdistribution_agents d on d.id = a.agent_id
where d.subscriber_db <> 'Virtual'
order by 1

The subscription(s) have been marked inactive ...

Very frequently transactional replications on servers send me the following error message:

Error Message : The subscription(s) have been marked inactive and must be reinitialized. NoSync subscriptions will need to be dropped and recreated.
Error Detail : The subscription(s) have been marked inactive and must be reinitialized. NoSync subscriptions
will need to be dropped and recreated. (Source: Server Name (Data source); Error number: 21074)

Even though "Subscriptions never expire" is marked.

I dont know the reason... Some said by default if nothing will replicate for 48 hours then it happened. some said a job that is responsible for mark subscription expired, if not run for specific time then it comes. but i dont get the xact reason and satisfactory answer but i got a cheat :)
Just go to distrubuition database and set the status of those publications to '2' and enjoy :)

USE distribution

Update [MSsubscriptions]
Set [status] = 2
where publisher_db = 'MarkedExpiredDB'

-- If anyone have better solution pls post.