Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Possible performance improvement (Bash and flat file)
Special Forums UNIX and Linux Applications Infrastructure Monitoring Possible performance improvement (Bash and flat file) Post 302419566 by Corona688 on Friday 7th of May 2010 02:01:06 PM
Old 05-07-2010
Quote:
Originally Posted by prafulnama
The catch is for certain metrics, it requires the last 5 values that it observed so I store those in a flat file and every time a new value is retrieved from the web page, that along with the stored values are used to compare against the threshold. Basically, I am doing everything sequentially so 2 loops, one to read in the IP and the next to do the web page download, threshold check, etc. Every time a new IP is added or a new metric needs to be monitored, the time taken to loop back to a machine increases. I wanted to see if there was a way to improve this?
It would help to see the actual code.
Quote:
Intuitively, I feel, because all historical values are stored in a single flat file, something like multi processing would not work since, a process would have that file locked. Any ideas?
Most systems don't do that kind of locking unless you explicitly ask for it. But having two processes simultaneously read the same file handle wouldn't be a great idea, they might each get half a line or somesuch. If you're just reading flat files line by line, you could try a 'reader' script that reads everything for them and parcels them out individually. That'd have some extra overhead for the extra process and its pipes, but would let more than one reader operate at once.

I'll need to see your actual code to help you here, I think, at least some of it. What needs to be optimized depends not just on what you're doing, but how you're doing it. If you're new to shell scripting there's some trivial design mistakes that could be causing slowdowns... excessive use of pipes and/or backticks is particularly bad. If you've got pipe chains on almost every line, there's probably much room for improvement. In my early scripting days I wrote a linewrapper in BASH that fed everything through about 9 sub-processes, it ended up processing at 10 kilobytes per second!
Last edited by Corona688; 05-07-2010 at 03:02 PM.. Reason: fix inexplicable doublepost
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Help with Flat Files Please!! BASH (New User)

Hello All, I am brand new to the UNIX world and so far and very intrigued and enjoy scripting. This is just a new language for me. I would really like assistance with the below request. Any help would be greatly appreciated! I want to create a flat file in Vi that has a header field and... (0 Replies)
Discussion started by: cyberjax21
0 Replies

2. Programming

File - reading - Performance improvement

Hi All I am reading a huge file of size 2GB atleast. I am reading each line and cutting certain columns and writing it to another file. Here is the logic. int main() { string u_line; string Char_List; string u_file; int line_pos; string temp_form_u_file; ... (10 Replies)
Discussion started by: dhanamurthy
10 Replies

3. Shell Programming and Scripting

Any improvement possible in this script

Hi! Thank you for the help yesterday This is the finished product There is one more thing I would like to do to it but I’m not to certain On how to proceed I would like to log all output to a log in order to Be able to roll back This script is meant to be used in repairing a... (4 Replies)
Discussion started by: Ex-Capsa
4 Replies

4. UNIX for Advanced & Expert Users

linux os improvement

can anyone help to share the knowledge on linux os improvement? 1) os account - use window AD authentication, such as ldap, but how to set /etc/passwd, where to put user home? 2) user account activity - how to log os user activity share the idea and what tools can do that...thx (5 Replies)
Discussion started by: goodbid
5 Replies

5. Shell Programming and Scripting

Display-performance in terminal, bash or python?

Heyas I've been working on my project TUI (Text User Interface) for quite some time now, its a hobby project, so nothing i sit in front of 8hrs/day. Since the only 'real' programming language i knw is Visual Basic, based upon early steps with MS-Batch files. When i 'joined' linux 3 years ago,... (7 Replies)
Discussion started by: sea
7 Replies

6. Shell Programming and Scripting

[BASH] Performance question - Script to STDOUT

Hello Coders Some time ago i was asking about python and bash performances, and i was told i could post the regarding code, and someone would kindly help to make it faster (if possible). If you have noted, i'm on the way to finalize, finish, stable TUI - Text(ual) User Interface. It is a... (6 Replies)
Discussion started by: sea
6 Replies

7. Shell Programming and Scripting

Performance improvement in grep

Below script is used to search numeric data from around 400 files in a folder. I have 300 such folders. Need help in performance improvement in the script. Below Script searches 20 such folders ( 300 files in each folder) simultaneously. This increases cpu utilization upto 90% What changes... (3 Replies)
Discussion started by: vegasluxor
3 Replies

8. Shell Programming and Scripting

Bash - array loop performance

Hi, another little question... "sn" is an array whose elements can vary from about 55,000 to about 150,000 elements. Each element consists of an integer between 0-255, eg: ${sn} contain the value: 103 . For a decrypt-procedure I need scroll all the elements 4 or 5 times. Here is an example of... (15 Replies)
Discussion started by: math4
15 Replies

9. OS X (Apple)

Create a bash array from a flat file of whitespaces only.

Hi guys and gals... MacBook Pro. OSX 10.13.2, default bash terminal. I have a flat file 1920 bytes in size of whitespaces only. I need to put every single whitespace character into a bash array cell. Below are two methods that work, but both are seriously ugly. The first one requires that I... (7 Replies)
Discussion started by: wisecracker
7 Replies

10. Shell Programming and Scripting

Bash script search, improve performance with large files

Hello, For several of our scripts we are using awk to search patterns in files with data from other files. This works almost perfectly except that it takes ages to run on larger files. I am wondering if there is a way to speed up this process or have something else that is quicker with the... (15 Replies)
Discussion started by: SDohmen
15 Replies

LEARN ABOUT MOJAVE

page_util_quote

page_util_quote(n)					      Parser generator tools						page_util_quote(n)

__________________________________________________________________________________________________________________________________________________

NAME

       page_util_quote - page character quoting utilities

SYNOPSIS

       package require page::util::quote  ?0.1?

       package require snit

       ::page::util::quote::unquote char

       ::page::util::quote::quote'tcl char

       ::page::util::quote::quote'tclstr char

       ::page::util::quote::quote'tclcom char

_________________________________________________________________

DESCRIPTION

       This package provides a few utility commands to convert characters into various forms.

API

       ::page::util::quote::unquote char
	      A  character,  as stored in an abstract syntax tree by a PEG processor (See the packages grammar::peg::interpreter, grammar::me, and
	      their relations), i.e. in some quoted form, is converted into the equivalent Tcl character. The character is returned as the  result
	      of the command.

       ::page::util::quote::quote'tcl char
	      This command takes a Tcl character (internal representation) and converts it into a string which is accepted by the Tcl parser, will
	      regenerate the character in question and is 7bit ASCII. The string is returned as the result of this command.

       ::page::util::quote::quote'tclstr char
	      This command takes a Tcl character (internal representation) and converts it into a string which is accepted by the Tcl  parser  and
	      will generate a human readable representation of the character in question.  The string is returned as the result of this command.

	      The  string  does not use any unprintable characters. It may use backslash-quoting. High UTF characters are quoted to avoid problems
	      with the still prevalent ascii terminals. It is assumed that the string will be used in a double-quoted environment.

       ::page::util::quote::quote'tclcom char
	      This command takes a Tcl character (internal representation) and converts it into a string which is accepted by the Tcl parser  when
	      used within a Tcl comment. The string is returned as the result of this command.

BUGS, IDEAS, FEEDBACK
       This  document,	will  undoubtedly  contain  bugs  and  other  problems.  Please report such in the category page of the Tcllib SF Trackers
       [http://sourceforge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you may have.

KEYWORDS

       page, parser generator, quoting, text processing

CATEGORY

       Page Parser Generator

COPYRIGHT

       Copyright (c) 2007 Andreas Kupries <andreas_kupries@users.sourceforge.net>

page									1.0							page_util_quote(n)
All times are GMT -4. The time now is 09:28 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy