Re: Best way set max heap size via env variables or program arguments?

[Xintong Song <to...@gmail.com>]

Hi Li,

Regarding your questions:

1. Is there actually a way to pass in the heap size via arguments to
> taskmanager.sh? Is passing -Dtaskmanager.heap.size supposed to work?


No, '-Dtaskmanager.heap.size' is not supposed to work. The '-D'
configurations are only parsed after the JVM is started, while
'taskmanager.heap.size' will be used for starting the JVM.

2.  If not, is there a recommended way to set the heap size by environment,
> like environmental variables?


Yes, these is an equivalent environment variable FLINK_TM_HEAP.


3. Also, the maximum heap size logged and -Xms and -Xmx is always a little
> smaller than the configured size (i.e. configuring 3000m results 2700m in
> the jvm arguments, 1024m results in 922), why is that?


The configuration key 'taskmanager.heap.size' is a bit inaccurate. The
config option actually also account for some off-heap memory, such as
network direct buffers and off-heap managed memory (if used). That's way
you see the java heap size is always slightly smaller than the configured
'taskmanager.heap.size'.


Thank you~

Xintong Song



On Wed, Jan 1, 2020 at 3:10 AM Li Peng <li...@doordash.com> wrote:

> Hey folks, we've been running a k8 flink application, using the
> taskmanager.sh script and passing in the -Djobmanager.heap.size=9000m and
> -Dtaskmanager.heap.size=7000m as options to the script. I noticed from the
> logs, that the Maximum heap size logged completely ignores these arguments,
> and just sets the heap to the default of 922M.
>
> I tested setting the taskmanager.heap.size and jobmanager.heap.size
> manually in flink-conf.yaml, and it does work as expected (minus the heap
> being set a little lower than configured). But since we want the
> application to pick up different memory settings based on the environment
> (local/staging/prod/etc), setting it in flink-conf isn't ideal.
>
> So my questions are:
>
> 1. Is there actually a way to pass in the heap size via arguments to
> taskmanager.sh? Is passing -Dtaskmanager.heap.size supposed to work?
> 2.  If not, is there a recommended way to set the heap size by
> environment, like environmental variables?
> 3. Also, the maximum heap size logged and -Xms and -Xmx is always a little
> smaller than the configured size (i.e. configuring 3000m results 2700m in
> the jvm arguments, 1024m results in 922), why is that?
>
> Thanks, and happy new year!
> Li
>
>

Re: Best way set max heap size via env variables or program arguments?

[Li Peng <li...@doordash.com>]

Awesome, thanks!

On Wed, Jan 1, 2020 at 6:17 PM Xintong Song <to...@gmail.com> wrote:

> Hi Li,
>
> Regarding your questions:
>
> 1. Is there actually a way to pass in the heap size via arguments to
>> taskmanager.sh? Is passing -Dtaskmanager.heap.size supposed to work?
>
>
> No, '-Dtaskmanager.heap.size' is not supposed to work. The '-D'
> configurations are only parsed after the JVM is started, while
> 'taskmanager.heap.size' will be used for starting the JVM.
>
> 2.  If not, is there a recommended way to set the heap size by
>> environment, like environmental variables?
>
>
> Yes, these is an equivalent environment variable FLINK_TM_HEAP.
>
>
> 3. Also, the maximum heap size logged and -Xms and -Xmx is always a little
>> smaller than the configured size (i.e. configuring 3000m results 2700m in
>> the jvm arguments, 1024m results in 922), why is that?
>
>
> The configuration key 'taskmanager.heap.size' is a bit inaccurate. The
> config option actually also account for some off-heap memory, such as
> network direct buffers and off-heap managed memory (if used). That's way
> you see the java heap size is always slightly smaller than the configured
> 'taskmanager.heap.size'.
>
>
> Thank you~
>
> Xintong Song
>
>
>
> On Wed, Jan 1, 2020 at 3:10 AM Li Peng <li...@doordash.com> wrote:
>
>> Hey folks, we've been running a k8 flink application, using the
>> taskmanager.sh script and passing in the -Djobmanager.heap.size=9000m and
>> -Dtaskmanager.heap.size=7000m as options to the script. I noticed from the
>> logs, that the Maximum heap size logged completely ignores these arguments,
>> and just sets the heap to the default of 922M.
>>
>> I tested setting the taskmanager.heap.size and jobmanager.heap.size
>> manually in flink-conf.yaml, and it does work as expected (minus the heap
>> being set a little lower than configured). But since we want the
>> application to pick up different memory settings based on the environment
>> (local/staging/prod/etc), setting it in flink-conf isn't ideal.
>>
>> So my questions are:
>>
>> 1. Is there actually a way to pass in the heap size via arguments to
>> taskmanager.sh? Is passing -Dtaskmanager.heap.size supposed to work?
>> 2.  If not, is there a recommended way to set the heap size by
>> environment, like environmental variables?
>> 3. Also, the maximum heap size logged and -Xms and -Xmx is always a
>> little smaller than the configured size (i.e. configuring 3000m results
>> 2700m in the jvm arguments, 1024m results in 922), why is that?
>>
>> Thanks, and happy new year!
>> Li
>>
>>