Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

memory, disk - scaling, performance - application architecture question

Posted on 2013-11-24
9
Medium Priority
?
247 Views
Last Modified: 2013-11-29
I am re-architecting an application that focuses on group collaboration around interactively building and annotating a complex diagram.

Average total data size for one group session for will probably be somewhere between 150KB and 1MB.

Currently the group session data is stored entirely in memory in a large object containing datasets and supporting variables.  This data is synced to disk during diagram update/writes.  

The data is kept in memory for fast diagram form refreshes (one participants does a small write, which might change the relationships on the diagram, which then has to be refreshed to all other participants).

My question has to do with performance versus scaling:
>  If 1 GB can store 1000 concurrent sessions (in my dreams), it doesn't seem like that would be a scaling bottleneck i.e. the server would bog down first, or I could add servers if I ran out of memory.
>  If I had to retrieve say 50KB from disk per diagram refresh (say one per second for each group session), it seems like that would be a big disk performance/scaling constraint.

So it seems like keeping the data in memory is almost necessary, to achieve scaling and maintain performance.

I'm trying to figure out if I've made some basic error in this thinking.

Any comments on these thoughts and assumptions would be appreciated.

Thanks!
0
Comment
Question by:codequest
  • 4
  • 2
  • 2
  • +1
9 Comments
 
LVL 45

Assisted Solution

by:AndyAinscow
AndyAinscow earned 400 total points
ID: 39674290
I tend to agree with you - keep it in memory if possible.
0
 
LVL 43

Assisted Solution

by:Eugene Z
Eugene Z earned 900 total points
ID: 39674713
it depends how much RAM you have and set for Sql server.

Please classify sql server part in this process:

" group collaboration around interactively building and annotating a complex diagram.
"
how did you calculate this?
"Average total data size for one group session for will probably be somewhere between 150KB and 1MB."


on what server\PC stored
"the group session data is stored entirely in memory in a large object containing datasets and supporting variables.  This data is synced to disk during diagram update/writes."
?

What method are you using to insure that is it in memory?

-------------------------

in any case you must use perfmon \sql profiler \DMVs for sql server  that will help you see real numbers
0
 
LVL 2

Author Comment

by:codequest
ID: 39675427
@EugeneZ

Thanks for input.  

1) I believe I considerably overestimated the amount of data that would be actively worked on and presented.   Better estimate would be 10KB.  This was calculated by considering table rows, fields, field usage and field sized (higher estimates did not account for null fields).

2) Data is currently maintained in memory in a ADO.NET DataSet that has 5 linked tables.

Unfortunately I have only a prototype and am unable to test high volumes in order to use the utilities you recommend.
0
Veeam Task Manager for Hyper-V

Task Manager for Hyper-V provides critical information that allows you to monitor Hyper-V performance by displaying real-time views of CPU and memory at the individual VM-level, so you can quickly identify which VMs are using host resources.

 
LVL 17

Assisted Solution

by:Gerald Connolly
Gerald Connolly earned 700 total points
ID: 39675768
If you are holding updates in memory, what are you doing to guard against equipment and/or power failure and the subsequent corruption of the DB on disk?
0
 
LVL 43

Accepted Solution

by:
Eugene Z earned 900 total points
ID: 39675872
there are much more elements that you need to conceder, check:

"out of memory exception ado.net dataset"
http://social.msdn.microsoft.com/Forums/en-US/41e1b19a-b5ee-4cf2-ac1e-ff0c9a35b961/out-of-memory-exception-adonet-dataset?forum=adodotnetdataset

also review a possibility to use stored procedures to calculate and  sql server to hold data

again there is not too much details about your apps architecture \tiers
0
 
LVL 2

Author Comment

by:codequest
ID: 39676148
From a similar question I posted on another site:

I'm re-architecting an asp.net application from web forms into MVC, moving from 2006 to 2013 asp.net technologies. The primary function of the app is group collaborative construction of a complex graphic/text data set. The plan is to run multiple concurrent SaaS group work sessions from a cloud.

The core graphic/text set ("data set") would consist of about 5 related tables, that need fairly complex business logic and associated multi-table queries to turn them into useful display information. The content of this data set needs to be sent to all participants, in a slightly customized way for each participant, every time it is updated by any participant.

In terms of volume, say 10 participants per group, one data set change every several seconds (in one session), the entire data set building up to approximately 10KB by the end of the session, so say an average of 5KB to retrieve the entire core data set from disk (if that were the path) for each send to the browser. That may be high but there could be a wide range of volumes.

The resulting pattern for a single session is then relatively infrequent, small updates to disk, followed by 10 times as many relatively large sends to the browser.
0
 
LVL 2

Author Comment

by:codequest
ID: 39676150
@connollyg

re what about memory failure:   the app currently uses DataSet/TableAdapter;  the writes are all updated to disk at the time they occur.
0
 
LVL 17

Assisted Solution

by:Gerald Connolly
Gerald Connolly earned 700 total points
ID: 39676814
re memory - I covered that under Equipment failure! Although you could go with a server that has RAID Memory!

re updates - You implied in your first post that some kind of write gathering was taking place. If your in-memory-db is really read-only its fine.
0
 
LVL 2

Author Closing Comment

by:codequest
ID: 39685904
I've concluded that performance and scaling questions are completely non-trivial, and so my question can't really be conclusively answered.  Inputs here have been valuable in reaching that conclusion, so points are rewarded accordingly.
0

Featured Post

Important Lessons on Recovering from Petya

In their most recent webinar, Skyport Systems explores ways to isolate and protect critical databases to keep the core of your company safe from harm.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
It is possible to export the data of a SQL Table in SSMS and generate INSERT statements. It's neatly tucked away in the generate scripts option of a database.
Familiarize people with the process of retrieving data from SQL Server using an Access pass-thru query. Microsoft Access is a very powerful client/server development tool. One of the ways that you can retrieve data from a SQL Server is by using a pa…
This video shows, step by step, how to configure Oracle Heterogeneous Services via the Generic Gateway Agent in order to make a connection from an Oracle session and access a remote SQL Server database table.

876 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question