how to start cassandra server

Question

I'm trying to start cassandra server

C:\Program Files\DataStax Community\apache-cassandra\bin>cassandra

but it is giving me the following error:

WARNING! Powershell script execution unavailable.

Please use 'powershell Set-ExecutionPolicy Unrestricted' on this user-account to run cassandra with fully featured functionality on this platform.

Starting with legacy startup options
Starting Cassandra Server

Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.

I also tried powershell Set-ExecutionPolicy Unrestricted but still gives some errors... like

C:\Program Files\DataStax Community\apache-cassandra\bin>powershell Set-ExecutionPolicy Unrestricted 

C:\Program Files\DataStax Community\apache-cassandra\bin>cassandra 

Detected powershell execution permissions. Running with enhanced startup scripts.

This following statement comes in red colour

The term '/' is not recognized as a cmdlet, function, operable program, or
script file. Verify the term and try again.
At line:1 char:2
+ /f <<<< ile C:\Program Files\DataStax Community\apache-cassandra\\bin\cassandra.ps1

If it's still not clear I attached an image:

Answer 1

Powershell permissions

As the error states, you need to grant Powershell permissions to the Windows account running the Cassandra script.

You can grant permissions to all Windows accounts on your machine with:

C:\> powershell Set-ExecutionPolicy Unrestricted

WARNING: You need to run the command prompt as an administrator for the command above to work.

As an alternative, you can grant unrestricted access just for your current user with:

C:\> powershell Set-ExecutionPolicy -Scope CurrentUser Unrestricted

Heap size

As a side note, this error indicates that you don't have enough RAM on your machine to run Cassandra with the default configuration:

Error occurred during initialization of VM
Could not reserve enough space for object heap

My guess is that your laptop/desktop only has 8GB of RAM. By default, Cassandra will attempt to start with 2GB of memory allocated to the heap but if there isn't enough free memory, Java will fail to reserve it.

Try to start Cassandra with a more conservative allocation of 1GB for max heap size and 400MB for NewGen by uncommenting the following lines in the "Heap Settings" section of conf/jvm.options:

-Xms1G
-Xmx1G
-Xmn400M

Windows support

I wanted to let you know that there is very limited Windows support in Cassandra 3.11 and there are several known issues that will not be fixed due to limitations in the operating system.

Furthermore, Windows support has been completely dropped in Cassandra 4.0 due to lack of maintainers and testing (CASSANDRA-16171).

As a workaround, we recommend the following:

• Deploy Cassandra in Docker
• Deploy Cassandra in a VM using software like VirtualBox
• Deploy K8ssandra.io

If you just want to build apps with Cassandra as a backend, Astra DB has a free tier that lets you launch a Cassandra cluster in a few clicks with no credit card required. Cheers!

Answer 2

I am studding Cassandra and I had the same issue. Follow the steps below to start it. I hope it help you.

1 - To open windows variables editor:

2 - Add the following variables according to your Java physical path (64 bits), Cassandra physical path and Java Memory Option. In my case:

JAVA_HOME = C:\Program Files\Java\jre1.8.0_221

CASSANDRA_HOME = C:\Program Files (x86)\apache-cassandra-3.11.4

_JAVA_OPTIONS = -Xmx2048‬M

3 - To open your powershell as administrator

4 - Access your Cassandra folder:

5 - Execute the command ".\cassandra" then your cassandra will start.