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From Pat Ferrel <...@occamsmachete.com>
Subject Re: Where does the Driver run?
Date Sun, 24 Mar 2019 22:09:00 GMT
2 Slaves, one of which is also Master.

Node 1 & 2 are slaves. Node 1 is where I run start-all.sh.

The machines both have 60g of free memory (leaving about 4g for the master
process on Node 1). The only constraint to the Driver and Executors is
spark.driver.memory = spark.executor.memory = 60g

BTW I would expect this to create one Executor, one Driver, and the Master
on 2 Workers.




From: Andrew Melo <andrew.melo@gmail.com> <andrew.melo@gmail.com>
Reply: Andrew Melo <andrew.melo@gmail.com> <andrew.melo@gmail.com>
Date: March 24, 2019 at 12:46:35 PM
To: Pat Ferrel <pat@occamsmachete.com> <pat@occamsmachete.com>
Cc: Akhil Das <akhld@hacked.work> <akhld@hacked.work>, user
<user@spark.apache.org> <user@spark.apache.org>
Subject:  Re: Where does the Driver run?

Hi Pat,

On Sun, Mar 24, 2019 at 1:03 PM Pat Ferrel <pat@occamsmachete.com> wrote:

> Thanks, I have seen this many times in my research. Paraphrasing docs: “in
> deployMode ‘cluster' the Driver runs on a Worker in the cluster”
>
> When I look at logs I see 2 executors on the 2 slaves (executor 0 and 1
> with addresses that match slaves). When I look at memory usage while the
> job runs I see virtually identical usage on the 2 Workers. This would
> support your claim and contradict Spark docs for deployMode = cluster.
>
> The evidence seems to contradict the docs. I am now beginning to wonder if
> the Driver only runs in the cluster if we use spark-submit????
>

Where/how are you starting "./sbin/start-master.sh"?

Cheers
Andrew


>
>
>
> From: Akhil Das <akhld@hacked.work> <akhld@hacked.work>
> Reply: Akhil Das <akhld@hacked.work> <akhld@hacked.work>
> Date: March 23, 2019 at 9:26:50 PM
> To: Pat Ferrel <pat@occamsmachete.com> <pat@occamsmachete.com>
> Cc: user <user@spark.apache.org> <user@spark.apache.org>
> Subject:  Re: Where does the Driver run?
>
> If you are starting your "my-app" on your local machine, that's where the
> driver is running.
>
> [image: image.png]
>
> Hope this helps.
> <https://spark.apache.org/docs/latest/cluster-overview.html>
>
> On Sun, Mar 24, 2019 at 4:13 AM Pat Ferrel <pat@occamsmachete.com> wrote:
>
>> I have researched this for a significant amount of time and find answers
>> that seem to be for a slightly different question than mine.
>>
>> The Spark 2.3.3 cluster is running fine. I see the GUI on “
>> http://master-address:8080", there are 2 idle workers, as configured.
>>
>> I have a Scala application that creates a context and starts execution of
>> a Job. I *do not use spark-submit*, I start the Job programmatically and
>> this is where many explanations forks from my question.
>>
>> In "my-app" I create a new SparkConf, with the following code (slightly
>> abbreviated):
>>
>>       conf.setAppName(“my-job")
>>       conf.setMaster(“spark://master-address:7077”)
>>       conf.set(“deployMode”, “cluster”)
>>       // other settings like driver and executor memory requests
>>       // the driver and executor memory requests are for all mem on the
>> slaves, more than
>>       // mem available on the launching machine with “my-app"
>>       val jars = listJars(“/path/to/lib")
>>       conf.setJars(jars)
>>       …
>>
>> When I launch the job I see 2 executors running on the 2 workers/slaves.
>> Everything seems to run fine and sometimes completes successfully. Frequent
>> failures are the reason for this question.
>>
>> Where is the Driver running? I don’t see it in the GUI, I see 2 Executors
>> taking all cluster resources. With a Yarn cluster I would expect the
>> “Driver" to run on/in the Yarn Master but I am using the Spark Standalone
>> Master, where is the Drive part of the Job running?
>>
>> If is is running in the Master, we are in trouble because I start the
>> Master on one of my 2 Workers sharing resources with one of the Executors.
>> Executor mem + driver mem is > available mem on a Worker. I can change this
>> but need so understand where the Driver part of the Spark Job runs. Is it
>> in the Spark Master, or inside and Executor, or ???
>>
>> The “Driver” creates and broadcasts some large data structures so the
>> need for an answer is more critical than with more typical tiny Drivers.
>>
>> Thanks for you help!
>>
>
>
> --
> Cheers!
>
>

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