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Posted to mapreduce-user@hadoop.apache.org by ricky l <ri...@gmail.com> on 2014/02/07 16:58:34 UTC
meaning or usage of reserved containers in YARN Capacity scheduler
Hi all,
I have a question about reserved containers in the YARN capacity
scheduler. After reading the source code and related document, it is
not very clear. What is the purpose or practical usage of the reserved
container? thx.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by ricky l <ri...@gmail.com>.
Thanks, Arun. The scenario makes sense!! thx.
On Mon, Feb 24, 2014 at 5:56 PM, Arun C Murthy <ac...@hortonworks.com> wrote:
> Apologies for the late reply.
>
> The concept of reservation is used to prevent starvation.
>
> For e.g. let's say you have 2 machines with 8G each. Now each of those are
> running containers which take up 6G on nodeA and 7G on nodeB.
>
> Another application comes in and then asks for a single container of 4G,
> which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is
> reserved on nodeA and is given to the app only when it's available... else,
> this application would be 'starved' if other apps came in and asked for 1G
> or 2G and would hence, 4G would never be freed up.
>
> Hope that helps.
>
> Arun
>
> On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
>
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
>
>
> --
> Arun C. Murthy
> Hortonworks Inc.
> http://hortonworks.com/
>
>
>
> CONFIDENTIALITY NOTICE
> NOTICE: This message is intended for the use of the individual or entity to
> which it is addressed and may contain information that is confidential,
> privileged and exempt from disclosure under applicable law. If the reader of
> this message is not the intended recipient, you are hereby notified that any
> printing, copying, dissemination, distribution, disclosure or forwarding of
> this communication is strictly prohibited. If you have received this
> communication in error, please contact the sender immediately and delete it
> from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by ricky l <ri...@gmail.com>.
Thanks, Arun. The scenario makes sense!! thx.
On Mon, Feb 24, 2014 at 5:56 PM, Arun C Murthy <ac...@hortonworks.com> wrote:
> Apologies for the late reply.
>
> The concept of reservation is used to prevent starvation.
>
> For e.g. let's say you have 2 machines with 8G each. Now each of those are
> running containers which take up 6G on nodeA and 7G on nodeB.
>
> Another application comes in and then asks for a single container of 4G,
> which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is
> reserved on nodeA and is given to the app only when it's available... else,
> this application would be 'starved' if other apps came in and asked for 1G
> or 2G and would hence, 4G would never be freed up.
>
> Hope that helps.
>
> Arun
>
> On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
>
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
>
>
> --
> Arun C. Murthy
> Hortonworks Inc.
> http://hortonworks.com/
>
>
>
> CONFIDENTIALITY NOTICE
> NOTICE: This message is intended for the use of the individual or entity to
> which it is addressed and may contain information that is confidential,
> privileged and exempt from disclosure under applicable law. If the reader of
> this message is not the intended recipient, you are hereby notified that any
> printing, copying, dissemination, distribution, disclosure or forwarding of
> this communication is strictly prohibited. If you have received this
> communication in error, please contact the sender immediately and delete it
> from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by ricky l <ri...@gmail.com>.
Thanks, Arun. The scenario makes sense!! thx.
On Mon, Feb 24, 2014 at 5:56 PM, Arun C Murthy <ac...@hortonworks.com> wrote:
> Apologies for the late reply.
>
> The concept of reservation is used to prevent starvation.
>
> For e.g. let's say you have 2 machines with 8G each. Now each of those are
> running containers which take up 6G on nodeA and 7G on nodeB.
>
> Another application comes in and then asks for a single container of 4G,
> which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is
> reserved on nodeA and is given to the app only when it's available... else,
> this application would be 'starved' if other apps came in and asked for 1G
> or 2G and would hence, 4G would never be freed up.
>
> Hope that helps.
>
> Arun
>
> On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
>
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
>
>
> --
> Arun C. Murthy
> Hortonworks Inc.
> http://hortonworks.com/
>
>
>
> CONFIDENTIALITY NOTICE
> NOTICE: This message is intended for the use of the individual or entity to
> which it is addressed and may contain information that is confidential,
> privileged and exempt from disclosure under applicable law. If the reader of
> this message is not the intended recipient, you are hereby notified that any
> printing, copying, dissemination, distribution, disclosure or forwarding of
> this communication is strictly prohibited. If you have received this
> communication in error, please contact the sender immediately and delete it
> from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by ricky l <ri...@gmail.com>.
Thanks, Arun. The scenario makes sense!! thx.
On Mon, Feb 24, 2014 at 5:56 PM, Arun C Murthy <ac...@hortonworks.com> wrote:
> Apologies for the late reply.
>
> The concept of reservation is used to prevent starvation.
>
> For e.g. let's say you have 2 machines with 8G each. Now each of those are
> running containers which take up 6G on nodeA and 7G on nodeB.
>
> Another application comes in and then asks for a single container of 4G,
> which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is
> reserved on nodeA and is given to the app only when it's available... else,
> this application would be 'starved' if other apps came in and asked for 1G
> or 2G and would hence, 4G would never be freed up.
>
> Hope that helps.
>
> Arun
>
> On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
>
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
>
>
> --
> Arun C. Murthy
> Hortonworks Inc.
> http://hortonworks.com/
>
>
>
> CONFIDENTIALITY NOTICE
> NOTICE: This message is intended for the use of the individual or entity to
> which it is addressed and may contain information that is confidential,
> privileged and exempt from disclosure under applicable law. If the reader of
> this message is not the intended recipient, you are hereby notified that any
> printing, copying, dissemination, distribution, disclosure or forwarding of
> this communication is strictly prohibited. If you have received this
> communication in error, please contact the sender immediately and delete it
> from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by Arun C Murthy <ac...@hortonworks.com>.
Apologies for the late reply.
The concept of reservation is used to prevent starvation.
For e.g. let's say you have 2 machines with 8G each. Now each of those are running containers which take up 6G on nodeA and 7G on nodeB.
Another application comes in and then asks for a single container of 4G, which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is reserved on nodeA and is given to the app only when it's available… else, this application would be 'starved' if other apps came in and asked for 1G or 2G and would hence, 4G would never be freed up.
Hope that helps.
Arun
On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/
--
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to
which it is addressed and may contain information that is confidential,
privileged and exempt from disclosure under applicable law. If the reader
of this message is not the intended recipient, you are hereby notified that
any printing, copying, dissemination, distribution, disclosure or
forwarding of this communication is strictly prohibited. If you have
received this communication in error, please contact the sender immediately
and delete it from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by Arun C Murthy <ac...@hortonworks.com>.
Apologies for the late reply.
The concept of reservation is used to prevent starvation.
For e.g. let's say you have 2 machines with 8G each. Now each of those are running containers which take up 6G on nodeA and 7G on nodeB.
Another application comes in and then asks for a single container of 4G, which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is reserved on nodeA and is given to the app only when it's available… else, this application would be 'starved' if other apps came in and asked for 1G or 2G and would hence, 4G would never be freed up.
Hope that helps.
Arun
On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/
--
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to
which it is addressed and may contain information that is confidential,
privileged and exempt from disclosure under applicable law. If the reader
of this message is not the intended recipient, you are hereby notified that
any printing, copying, dissemination, distribution, disclosure or
forwarding of this communication is strictly prohibited. If you have
received this communication in error, please contact the sender immediately
and delete it from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by Arun C Murthy <ac...@hortonworks.com>.
Apologies for the late reply.
The concept of reservation is used to prevent starvation.
For e.g. let's say you have 2 machines with 8G each. Now each of those are running containers which take up 6G on nodeA and 7G on nodeB.
Another application comes in and then asks for a single container of 4G, which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is reserved on nodeA and is given to the app only when it's available… else, this application would be 'starved' if other apps came in and asked for 1G or 2G and would hence, 4G would never be freed up.
Hope that helps.
Arun
On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/
--
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to
which it is addressed and may contain information that is confidential,
privileged and exempt from disclosure under applicable law. If the reader
of this message is not the intended recipient, you are hereby notified that
any printing, copying, dissemination, distribution, disclosure or
forwarding of this communication is strictly prohibited. If you have
received this communication in error, please contact the sender immediately
and delete it from your system. Thank You.
Re: meaning or usage of reserved containers in YARN Capacity scheduler
Posted by Arun C Murthy <ac...@hortonworks.com>.
Apologies for the late reply.
The concept of reservation is used to prevent starvation.
For e.g. let's say you have 2 machines with 8G each. Now each of those are running containers which take up 6G on nodeA and 7G on nodeB.
Another application comes in and then asks for a single container of 4G, which can't be allocated anywhere in the cluster. In this case (e.g.) 4G is reserved on nodeA and is given to the app only when it's available… else, this application would be 'starved' if other apps came in and asked for 1G or 2G and would hence, 4G would never be freed up.
Hope that helps.
Arun
On Feb 7, 2014, at 7:58 AM, ricky l <ri...@gmail.com> wrote:
> Hi all,
>
> I have a question about reserved containers in the YARN capacity
> scheduler. After reading the source code and related document, it is
> not very clear. What is the purpose or practical usage of the reserved
> container? thx.
--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/
--
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to
which it is addressed and may contain information that is confidential,
privileged and exempt from disclosure under applicable law. If the reader
of this message is not the intended recipient, you are hereby notified that
any printing, copying, dissemination, distribution, disclosure or
forwarding of this communication is strictly prohibited. If you have
received this communication in error, please contact the sender immediately
and delete it from your system. Thank You.