Blocking execute fethod from com.datastax.driver.core.Session
public ResultSet execute(Statement statement);
Comment on this method:
This method blocks until at least some result has been received from the database. However, for SELECT queries, it does not guarantee that the result has been received in full. But it does guarantee that some response has been received from the database, and in particular guarantee that if the request is invalid, an exception will be thrown by this method.
Non-blocking execute fethod from com.datastax.driver.core.Session
public ResultSetFuture executeAsync(Statement statement);
This method does not block. It returns as soon as the query has been passed to the underlying network stack. In particular, returning from this method does not guarantee that the query is valid or has even been submitted to a live node. Any exception pertaining to the failure of the query will be thrown when accessing the {@link ResultSetFuture}.
I have 02 questions about them, thus it would be great if you can help me to understand them.
Let's say I have 1 million of records and I want all of them to be arrived in the database (without any lost).
Question 1: If I have n number of threads, all threads will have the same amount of records they need to send to the database. All of them continue sending multiple insert queries to cassandra using blocking execute call. If I increase the value of n, will it also helps to speed up the time that I need to insert all records to cassandra?
Will this cause performance problem for cassandra? Does Cassandra have to make sure that for every single insert record, all the nodes in the clusters should know about the new record immediately? In order to maintain the consistency in data. (I assume cassandra node won't even think about using the local machine time for controlling the record insertion time).
Question 2: With non-blocking execute, how can I assure that all of the insertions is successful? The only way I know is waiting for the ResultSetFuture to check the execution of the insert query. Is there any better way I can do ? Is there a higher chance that non-blocking execute is easier to fail then blocking execute?
Thank you very much for your helps.