The index was previously created on ElasticSearch Version 1.4, recently the ElasticSearch was upgraded to 1.7 after I took over the work.
I have checked with the status of the index and it states no-merges have taken place as shown in the diagram below.
I have tried to check the logs but for this index there are no logs detailing any error.
However, while going through different statuses - I think i need to upgrade the index. I am sorry a bit new to this advanced configurations of elasticsearch as previously we were using basic configurations with small tweaking. But now are thinking of moving to production so looking into these issues.
Underneath are the detail screenshots of the index.
If you see in the screenshot in couple of another the same issue has happened - One more addition to it in all these cases the Index has one 1 shard.