Interpreting what gets printed as one submits spark application

I am fairly new to spark. I configured 3 machines(2 slaves) on a standalone cluster. I just wanted to know what exactly is the meaning of: [Stage 0:==(25 + 4) / 500] This gets printed to the terminal when I submit my app. I understand

Re: How does one decide no of executors/cores/memory allocation?

I realize that there are a lot of ways to configure my application in spark. The part that is not clear is that how do I decide say for example in how many partitions should I divide my data or how much ram should I have or how many workers should one initialize? -- View this message in

How does one decide no of executors/cores/memory allocation?

How do I decide in how many partitions I break up my data into, how many executors should I have? I guess memory and cores will be allocated based on the number of executors I have. Thanks -- View this message in context: