Writes to Elastic search fails

I'm trying to collect network data and pushing to elastic store.
Some of the documents are not indexed(not stored). Is this expected.

Without more information it's extremely hard to help.

Have a look at https://www.elastic.co/help

I have created this gist to explain better.

I'm interested to know if the write fails are expected to occur.

Even though all 2000 inserts are acknowledged.

So you are checking the _bulk response payload and each document says ok?

I'm not using bulk.
In ack some are errors.

So what are the errors?

I was testing it again to get exact errors so the delay

 { [Error: Request Timeout after 30000ms]
  status: 408,
  displayName: 'RequestTimeout',
  message: 'Request Timeout after 30000ms' }

Am i missing anything.