title: What is the batch limit in Cassandra?
body: <p>I have a Java client that pushes (INSERT) records in batch to Cassandra cluster. The elements in the batch all have the same row key, so they all will be placed in the same node. Also I don't need the transaction to be atomic so I've been using unlogged batch.</p>
  
  <p>The number of INSERT commands in each batch depends on different factors, but can be anything between 5 to 50000. First I just put as many commands as I had in one batch and submitted it. This threw <code>com.datastax.driver.core.exceptions.InvalidQueryException: Batch too large</code>. Then I used a cap of 1000 INSERT per batch, and then down to 300. I noticed I'm just randomly guessing without knowing exactly where this limit comes from, which can cause trouble down the road.</p>
  
  <p>My question is, what is this limit? Can I modify it? How can I know how many elements can be placed in a batch? When my batch is "full"?</p>