Let's say I need 10000 ops/sec with a read:write ratio of 7:3

I'm trying with this:

mixed duration=6h cl=local_quorum keysize=100 'ratio(read=7,write=3)' -rate fixed="10000/s" -pop seq=1..10000 -mode user="user" password="pass" -node 1.1.1.1

Error:

Failed to parse parameter fixed.

Caused by:
    Invalid value =10000/s. Boolean flag cannot have any value.
Error: Failed to parse CLI arguments.

It doesn't show errors, if I replace fixed="10000/s" with threads=100. But I need a way to control the exact number of operations/second. Is there a way to achieve this? even with threads?

Let's say I need 10000 ops/sec with a read:write ratio of 7:3

I'm trying with this:

mixed duration=6h cl=local_quorum keysize=100 'ratio(read=7,write=3)' -rate fixed="10000/s" -pop seq=1..10000 -mode user="user" password="pass" -node 1.1.1.1

Error:

Failed to parse parameter fixed.

Caused by:
    Invalid value =10000/s. Boolean flag cannot have any value.
Error: Failed to parse CLI arguments.

It doesn't show errors, if I replace fixed="10000/s" with threads=100. But I need a way to control the exact number of operations/second. Is there a way to achieve this? even with threads?

• cassandra
• cqlsh
• cassandra-stress
• cassandra-stress-tool

• 1 Hi there! I don't know if that is even an option there. You could try out this OSS NoSQLBench (Use 5.21.4-release needs JDK21) with which you could specify rate=10000 and it will trigger 10000 ops/second. I hope that you will give that a try. Discord for help, Usage Patterns supported, Dev Introduction Video, repo – Madhavan Commented Feb 22 at 19:18
• Thanks for posting on Stack Overflow! A friendly reminder that this site is for getting help with coding, algorithm, or programming language problems so I voted to have your post moved to DBA Stack Exchange. For future reference, you should post DB admin/ops questions on dba.stackexchange/questions/ask?tags=cassandra. Cheers! – Erick Ramirez Commented Feb 26 at 2:08

1 Answer 1

In your command, you specified the rate as:

$ cassandra-stress ... -rate fixed="10000/s" ...

Looking at the code for o.a.c.stress/settings/SettingsRate.java, your usage is incorrect.

You'll either need to (a) set the minimum and maximum number of threads, or (b) explicitly set the number of threads in order to specify the operations/sec or throttle:

Usage: -rate threads=? [throttle=?] [fixed=?]
 OR 
Usage: -rate [threads>=?] [threads<=?] [auto]

If you modify your command to include the threads count, you should be able to specify a value for fixed. For example:

$ cassandra-stress ... -rate threads=100 fixed="10000/s" ...

For what it's worth, you didn't specify which version of Cassandra you're running so I linked to version 5.0 of the code. Cheers!