[jira] [Comment Edited] (STORM-594) Auto-Scaling Resources in a Topology

["Memory Lake (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/STORM-594?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14641826#comment-14641826 ] 

Memory Lake edited comment on STORM-594 at 7/26/15 2:19 AM:
------------------------------------------------------------

Thank you for your input. I have carefully read the paper from UIUC, one thing still concerns me is that the length of input queue which they claimed is a built-in metric in Storm is not that easy to retrieve. According to my observation there is no such metric in the UI daemon or any other part of Storm’s implementation. Maybe I didn’t manage to understand it correctly, but missing this critical information makes their bottleneck detection hard to reproduce in my system and thus I have to figure it out on my own, which by the way, is kind of similar to what you have proposed above and is mainly based on the capacity obtained from the monitor. Besides, in my case even the same size of input stream could potentially induce a varying resource demand, since some logic in bolts are basically depends on the type and fields of tuples. Have you guys taken this into your considerations?


was (Author: memorylake@qq.com):
Thank you for your input. I have carefully read the paper from UIUC, one thing still concerns me is that the length of input queue which they claimed is a built-in metric in Storm is not that easy to retrieve. According to my observation there is no such metric in the UI daemon or any other part of Storm’s implementation. Maybe I didn’t manage to understand it out correctly, but missing this critical information makes their bottleneck detection hard to reproduce in my system. Besides, in my case even the same size of input stream could potentially induce a varying resource demand, since some logic in bolts are basically depends on the type and fields of tuples. Have you guys taken this into your considerations?

> Auto-Scaling Resources in a Topology
> ------------------------------------
>
>                 Key: STORM-594
>                 URL: https://issues.apache.org/jira/browse/STORM-594
>             Project: Apache Storm
>          Issue Type: New Feature
>            Reporter: HARSHA BALASUBRAMANIAN
>            Assignee: Pooyan Jamshidi
>            Priority: Minor
>         Attachments: Algorithm for Auto-Scaling.pdf, Project Plan and Scope.pdf
>
>   Original Estimate: 504h
>  Remaining Estimate: 504h
>
> A useful feature missing in Storm topologies is the ability to auto-scale resources, based on a pre-configured metric. The feature proposed here aims to build such a auto-scaling mechanism using a feedback system. A brief overview of the feature is provided here. The finer details of the required components and the scaling algorithm (uses a Feedback System) are provided in the PDFs attached.
> Brief Overview:
> Topologies may get created with or (ideally) without parallelism hints and tasks in their bolts and spouts, before submitting them, If auto-scaling is set in the topology (using a Boolean flag), the topology will also get submitted to the auto-scale module.
> The auto-scale module will read a pre-configured metric (threshold/min) from a configuration file. Using this value, the topology's resources will be modified till the threshold is reached. At each stage in the auto-scale module's execution, feedback from the previous execution will be used to tune the resources.
> The systems that need to be in place to achieve this are:
> 1. Metrics which provide the current threshold (no: of acks per minute) for a topology's spouts and bolts.
> 2. Access to Storm's CLI tool which can change a topology's resources are runtime.
> 3. A new java or clojure module which runs within the Nimbus daemon or in parallel to it. This will be the auto-scale module.
> Limitations: (This is not an exhaustive list. More will be added as the design matures. Also, some of the points here may get resolved)
> To test the feature there will be a number of limitations in the first release. As the feature matures, it will be allowed to scale more
> 1. The auto-scale module will be limited to a few topologies (maybe 4 or 5 at maximum)
> 2. New bolts will not be added to scale a topology. This feature will be limited to increasing the resources within the existing topology.
> 3. Topology resources will not be decreased when it is running at more than the required number (except for a few cases)
> 4. This feature will work only for long-running topologies where the input threshold can become equal to or greater than the required threshold



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)