Flex Protocol Scripting in LR

Introduction

Adobe Flex is a software development kit released by Adobe Systems for the development and deployment of cross-platform rich Internet applications based on the Adobe Flash platform. Flex applications can be written using Adobe Flex Builderor by using the freely available Flex compiler from Adobe.

Developers use two core languages to create Flex applications. The first core language is MXML, the Macromedia Flex Mark-up Language, which includes a rich set of XML tags that allows developers to layout user interfaces. Some MXML constructs allow you to call remote objects, store data returned in a model, and customize your own look and feel to MXML components.

The second core language for Flex development is Action Script 2.0, which is similar to JavaScript. Action Script elements are coded inside MXML pages has robust event handling capabilities to allow the application to respond to dynamic user interactions. Unlike JavaScript, since Action Script runs inside the Flash plug-in there is no need to rewrite several versions of the same code to support different browsers.

The Flex server is responsible for translating the MXML and Action Script components into Flash byte code in the form of .SWF files. The SWF file is executed on the client in the Flash runtime environment. The Flex server provides other services such as caching, concurrency, and handling remote object requests. 

Flex Protocol with LR

VuGen allows you to create Vusers that emulate the protocol suite provided with the Flex 2 SDK.

RIAs are lightweight online programs that provide users with more dynamic control than with a standard web page. Like Web applications built with AJAX, Flex applications are more responsive, because the application does not need to load a new Web page every time the user takes action. However, unlike working with AJAX, Flex is independent of browser implementations such as JavaScript or CSS. The framework runs on Adobe's cross-platform Flash Player. 

Pre-requisite

•     Load Runner 11.0 support the flex with the patch3
•     JRE 6.0 
•     Adobe flash player 10 and higher

Environment Variables

Verify for the following environment variables in Windows Operating system.

The environment variables can be reached by following the below steps:

1.    Right-click “My Computer”. Go to properties.

2.    Go to Advanced Tab

3.    Click on the Environment Variables button

Click on the “New “button under System variables and enter the below values:

Variable name: HP_FLEX_JAVA_LOG_FILE

Variable value: C:\flex.log

Variable name: VUGEN_PATH

Variable value: C:\Program Files\HP\Virtual User Generator\

Variable name: ANALYSIS_PATH

Variable value: C:\Program Files\HP\LoadRunner\

* The HP_FLEX_JAVA_LOG_FILE is used to generate the log file which will help us to identify the classes involved in a particular transaction.

This log file will be very useful for debugging. Ensure that there are no errors in the flex log file after recording.

Recording Options

The following recording options need to be considered before recording in flex protocol:

·         Go to Tools à Recording Options in LoadRunner.

·         Under Script Check the check box against “Generate recorded event logs”. This setting helps to generate the log files for debugging

·         Under Protocols tab select all three check boxes viz.,

o    Action Message Format (AMF)

o    Flex

o    Web(HTTP/HTML)

·         Under Recording, select HTML based script.

·         Select HTML Advanced button and select “A script that contains explicit URLs only (e.g.web_url, web_submit_data)”  and “Record in separate steps and use concurrent grops” for Non HTML – generated elements

·         Under Code generation select Encode AMF3 using external parser.And provide the below jar files location under Value column.

o    flex-messaging-common.jar

o    flex-messaging-core.jar

o    (Any application specific jars.The jars are dependent on the transaction and should be verified before recording every transaction)  

·         Under Port-Mapping, click on Options. Under Advanced Port Mapping Settings à Change Log level to Advanced Debug. - This setting would enable to generate flex log in C:\ drive.

  

·         The Advanced tab under HTTP properties is the standard one. 

·         Under Correlation tab, uncheck the “Enable correlation during recording” check box.

 

Post Recording Verification

After recording verify following:

1.    A file by name “flex. log” should be generated in C:\ drive.

2.    flex_amf_call should be generated with readable XML’s and not the binary format for all requests.

Correlation in Flex Scripts

Flex applications often contain dynamic data, data that changes each time you run the script. For example, the object name may change from run to run.

When you record a Vuser script, VuGen records a set of data and argument values. When you replay the script, however, the server may reject these arguments and issue an error. This error could be the result of dynamic data that is outdated and no longer accepted by the server.

To overcome this, you apply correlation to your script:

➤ Save the server response in preparation for extracting the required values.

➤ Extract the required values from the server response.

➤ Save the values to a parameter.

➤ Use those parameters as input to your Flex requests.

These errors are not always obvious, and you may only detect them by carefully examining Vuser log files. If you encounter an error when running your Vuser, examine the script at the point where the error occurred. Often, correlation will solve the problem by enabling you to use the results of one statement as input for another.

To perform correlation:

1 Locate the step in your script that failed due to dynamic values that need correlation.

Use the Replay Log to assist you in finding the problematic step.

2 Identify the server response with the correct value in one of the previous steps.

Double-Click the error in the Replay log to go to the step with the error. Examine the preceding steps in Tree View and look for the value in the Server Response tab.

3 Save the entire server response to a parameter.

Before you extract the value, the entire server response should be saved to a parameter as follows:

➤ Right-click the step node (in the left Action pane) corresponding to the server response containing the value and select Properties.

➤ In the Flex Call Properties dialog box, type a Response parameter name.

➤ Click OK to save the new parameter name.

4 Save the original server response value to a parameter.

➤ In the Replay Snapshot: Response Data, right-click the node above the value (for example, string), and select Save value in parameter.

 

In the XML Parameter Properties dialog, specify a parameter Name. You will use this name in subsequent steps.

➤ Click OK. The script will now contain a new function, lr_xml_get_values.

5 Insert the parameter in the subsequent calls.

In VuGen edit view, beginning with the call that failed, replace the value in all subsequent calls to the object with the parameter that you defined:

➤ Right-click the step node (in the Action pane) corresponding to the failed call and select Properties.

➤ Locate the argument that required correlation.

➤ In the Value box, type the parameter name in curly brackets, for example, {ParamValue_string}.

Click OK

 

6 Run the script.

Make sure that VuGen properly substitutes the argument value with the parameter value that you saved.

Some Important JAR files needed are 

 

We need application JAR files as well along with these JAR files from developer to generate the decoded AMF calls in the scripts else we can’t parse and correlate the requests.

SAR COMMANDS UNIX

Using sar you can monitor performance of various Linux subsystems (CPU, Memory, I/O..) in real time.

Using sar, you can also collect all performance data on an on-going basis, store them, and do historical analysis to identify bottlenecks.

Sar is part of the sysstat package.

This article explains how to install and configure sysstat package (which contains sar utility) and explains how to monitor the following Linux performance statistics using sar.

1. Collective CPU usage
2. Individual CPU statistics
3. Memory used and available
4. Swap space used and available
5. Overall I/O activities of the system
6. Individual device I/O activities
7. Context switch statistics
8. Run queue and load average data
9. Network statistics
10. Report sar data from a specific time

This is the only guide you’ll need for sar utility. So, bookmark this for your future reference.

I. Install and Configure Sysstat

Install Sysstat Package

First, make sure the latest version of sar is available on your system. Install it using any one of the following methods depending on your distribution.

sudo apt-get install sysstat
(or)
yum install sysstat
(or)
rpm -ivh sysstat-10.0.0-1.i586.rpm

Install Sysstat from Source

wget http://pagesperso-orange.fr/sebastien.godard/sysstat-10.0.0.tar.bz2

tar xvfj sysstat-10.0.0.tar.bz2

cd sysstat-10.0.0

./configure --enable-install-cron

Note: Make sure to pass the option –enable-install-cron. This does the following automatically for you. If you don’t configure sysstat with this option, you have to do this ugly job yourself manually.

• Creates /etc/rc.d/init.d/sysstat
• Creates appropriate links from /etc/rc.d/rc*.d/ directories to /etc/rc.d/init.d/sysstat to start the sysstat automatically during Linux boot process.
• For example, /etc/rc.d/rc3.d/S01sysstat is linked automatically to /etc/rc.d/init.d/sysstat

After the ./configure, install it as shown below.

make

make install

Note: This will install sar and other systat utilities under /usr/local/bin

Once installed, verify the sar version using “sar -V”. Version 10 is the current stable version of sysstat.

$ sar -V
sysstat version 10.0.0
(C) Sebastien Godard (sysstat  orange.fr)

Finally, make sure sar works. For example, the following gives the system CPU statistics 3 times (with 1 second interval).

$ sar 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:27:32 PM       CPU     %user     %nice   %system   %iowait    %steal     %idle
01:27:33 PM       all      0.00      0.00      0.00      0.00      0.00    100.00
01:27:34 PM       all      0.25      0.00      0.25      0.00      0.00     99.50
01:27:35 PM       all      0.75      0.00      0.25      0.00      0.00     99.00
Average:          all      0.33      0.00      0.17      0.00      0.00     99.50

Utilities part of Sysstat

Following are the other sysstat utilities.

• sar collects and displays ALL system activities statistics.
• sadc stands for “system activity data collector”. This is the sar backend tool that does the data collection.
• sa1 stores system activities in binary data file. sa1 depends on sadc for this purpose. sa1 runs from cron.
• sa2 creates daily summary of the collected statistics. sa2 runs from cron.
• sadf can generate sar report in CSV, XML, and various other formats. Use this to integrate sar data with other tools.
• iostat generates CPU, I/O statistics
• mpstat displays CPU statistics.
• pidstat reports statistics based on the process id (PID)
• nfsiostat displays NFS I/O statistics.
• cifsiostat generates CIFS statistics.

This article focuses on sysstat fundamentals and sar utility.

Collect the sar statistics using cron job – sa1 and sa2

Create sysstat file under /etc/cron.d directory that will collect the historical sar data.

# vi /etc/cron.d/sysstat
*/10 * * * * root /usr/local/lib/sa/sa1 1 1
53 23 * * * root /usr/local/lib/sa/sa2 -A

If you’ve installed sysstat from source, the default location of sa1 and sa2 is /usr/local/lib/sa. If you’ve installed using your distribution update method (for example: yum, up2date, or apt-get), this might be /usr/lib/sa/sa1 and /usr/lib/sa/sa2.

/usr/local/lib/sa/sa1

• This runs every 10 minutes and collects sar data for historical reference.
• If you want to collect sar statistics every 5 minutes, change */10 to */5 in the above /etc/cron.d/sysstat file.
• This writes the data to /var/log/sa/saXX file. XX is the day of the month. saXX file is a binary file. You cannot view its content by opening it in a text editor.
• For example, If today is 26th day of the month, sa1 writes the sar data to /var/log/sa/sa26
• You can pass two parameters to sa1: interval (in seconds) and count.
• In the above crontab example: sa1 1 1 means that sa1 collects sar data 1 time with 1 second interval (for every 10 mins).

/usr/local/lib/sa/sa2

• This runs close to midnight (at 23:53) to create the daily summary report of the sar data.
• sa2 creates /var/log/sa/sarXX file (Note that this is different than saXX file that is created by sa1). This sarXX file created by sa2 is an ascii file that you can view it in a text editor.
• This will also remove saXX files that are older than a week. So, write a quick shell script that runs every week to copy the /var/log/sa/* files to some other directory to do historical sar data analysis.

II. 10 Practical Sar Usage Examples

There are two ways to invoke sar.

1. sar followed by an option (without specifying a saXX data file). This will look for the current day’s saXX data file and report the performance data that was recorded until that point for the current day.
2. sar followed by an option, and additionally specifying a saXX data file using -f option. This will report the performance data for that particular day. i.e XX is the day of the month.

In all the examples below, we are going to explain how to view certain performance data for the current day. To look for a specific day, add “-f /var/log/sa/saXX” at the end of the sar command.

All the sar command will have the following as the 1st line in its output.

$ sar -u
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

• Linux 2.6.18-194.el5PAE – Linux kernel version of the system.
• (dev-db) – The hostname where the sar data was collected.
• 03/26/2011 – The date when the sar data was collected.
• _i686_ – The system architecture
• (8 CPU) – Number of CPUs available on this system. On multi core systems, this indicates the total number of cores.

1. CPU Usage of ALL CPUs (sar -u)

This gives the cumulative real-time CPU usage of all CPUs. “1 3″ reports for every 1 seconds a total of 3 times. Most likely you’ll focus on the last field “%idle” to see the cpu load.

$ sar -u 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:27:32 PM       CPU     %user     %nice   %system   %iowait    %steal     %idle
01:27:33 PM       all      0.00      0.00      0.00      0.00      0.00    100.00
01:27:34 PM       all      0.25      0.00      0.25      0.00      0.00     99.50
01:27:35 PM       all      0.75      0.00      0.25      0.00      0.00     99.00
Average:          all      0.33      0.00      0.17      0.00      0.00     99.50

Following are few variations:

• sar -u Displays CPU usage for the current day that was collected until that point.
• sar -u 1 3 Displays real time CPU usage every 1 second for 3 times.
• sar -u ALL Same as “sar -u” but displays additional fields.
• sar -u ALL 1 3 Same as “sar -u 1 3″ but displays additional fields.
• sar -u -f /var/log/sa/sa10 Displays CPU usage for the 10day of the month from the sa10 file.

2. CPU Usage of Individual CPU or Core (sar -P)

If you have 4 Cores on the machine and would like to see what the individual cores are doing, do the following.

“-P ALL” indicates that it should displays statistics for ALL the individual Cores.

In the following example under “CPU” column 0, 1, 2, and 3 indicates the corresponding CPU core numbers.

$ sar -P ALL 1 1
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:34:12 PM       CPU     %user     %nice   %system   %iowait    %steal     %idle
01:34:13 PM       all     11.69      0.00      4.71      0.69      0.00     82.90
01:34:13 PM         0     35.00      0.00      6.00      0.00      0.00     59.00
01:34:13 PM         1     22.00      0.00      5.00      0.00      0.00     73.00
01:34:13 PM         2      3.00      0.00      1.00      0.00      0.00     96.00
01:34:13 PM         3      0.00      0.00      0.00      0.00      0.00    100.00

“-P 1″ indicates that it should displays statistics only for the 2nd Core. (Note that Core number starts from 0).

$ sar -P 1 1 1
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:36:25 PM       CPU     %user     %nice   %system   %iowait    %steal     %idle
01:36:26 PM         1      8.08      0.00      2.02      1.01      0.00     88.89

Following are few variations:

• sar -P ALL Displays CPU usage broken down by all cores for the current day.
• sar -P ALL 1 3 Displays real time CPU usage for ALL cores every 1 second for 3 times (broken down by all cores).
• sar -P 1 Displays CPU usage for core number 1 for the current day.
• sar -P 1 1 3 Displays real time CPU usage for core number 1, every 1 second for 3 times.
• sar -P ALL -f /var/log/sa/sa10 Displays CPU usage broken down by all cores for the 10day day of the month from sa10 file.

3. Memory Free and Used (sar -r)

This reports the memory statistics. “1 3″ reports for every 1 seconds a total of 3 times. Most likely you’ll focus on “kbmemfree” and “kbmemused” for free and used memory.

$ sar -r 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

07:28:06 AM kbmemfree kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit  kbactive   kbinact
07:28:07 AM   6209248   2097432     25.25    189024   1796544    141372      0.85   1921060     88204
07:28:08 AM   6209248   2097432     25.25    189024   1796544    141372      0.85   1921060     88204
07:28:09 AM   6209248   2097432     25.25    189024   1796544    141372      0.85   1921060     88204
Average:      6209248   2097432     25.25    189024   1796544    141372      0.85   1921060     88204

Following are few variations:

• sar -r
• sar -r 1 3
• sar -r -f /var/log/sa/sa10

4. Swap Space Used (sar -S)

This reports the swap statistics. “1 3″ reports for every 1 seconds a total of 3 times. If the “kbswpused” and “%swpused” are at 0, then your system is not swapping.

$ sar -S 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

07:31:06 AM kbswpfree kbswpused  %swpused  kbswpcad   %swpcad
07:31:07 AM   8385920         0      0.00         0      0.00
07:31:08 AM   8385920         0      0.00         0      0.00
07:31:09 AM   8385920         0      0.00         0      0.00
Average:      8385920         0      0.00         0      0.00

Following are few variations:

• sar -S
• sar -S 1 3
• sar -S -f /var/log/sa/sa10

Notes:

• Use “sar -R” to identify number of memory pages freed, used, and cached per second by the system.
• Use “sar -H” to identify the hugepages (in KB) that are used and available.
• Use “sar -B” to generate paging statistics. i.e Number of KB paged in (and out) from disk per second.
• Use “sar -W” to generate page swap statistics. i.e Page swap in (and out) per second.

5. Overall I/O Activities (sar -b)

This reports I/O statistics. “1 3″ reports for every 1 seconds a total of 3 times.

Following fields are displays in the example below.

• tps – Transactions per second (this includes both read and write)
• rtps – Read transactions per second
• wtps – Write transactions per second
• bread/s – Bytes read per second
• bwrtn/s – Bytes written per second

$ sar -b 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:56:28 PM       tps      rtps      wtps   bread/s   bwrtn/s
01:56:29 PM    346.00    264.00     82.00   2208.00    768.00
01:56:30 PM    100.00     36.00     64.00    304.00    816.00
01:56:31 PM    282.83     32.32    250.51    258.59   2537.37
Average:       242.81    111.04    131.77    925.75   1369.90

Following are few variations:

• sar -b
• sar -b 1 3
• sar -b -f /var/log/sa/sa10

Note: Use “sar -v” to display number of inode handlers, file handlers, and pseudo-terminals used by the system.

6. Individual Block Device I/O Activities (sar -d)

To identify the activities by the individual block devices (i.e a specific mount point, or LUN, or partition), use “sar -d”

$ sar -d 1 1
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:59:45 PM       DEV       tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util
01:59:46 PM    dev8-0      1.01      0.00      0.00      0.00      0.00      4.00      1.00      0.10
01:59:46 PM    dev8-1      1.01      0.00      0.00      0.00      0.00      4.00      1.00      0.10
01:59:46 PM dev120-64      3.03     64.65      0.00     21.33      0.03      9.33      5.33      1.62
01:59:46 PM dev120-65      3.03     64.65      0.00     21.33      0.03      9.33      5.33      1.62
01:59:46 PM  dev120-0      8.08      0.00    105.05     13.00      0.00      0.38      0.38      0.30
01:59:46 PM  dev120-1      8.08      0.00    105.05     13.00      0.00      0.38      0.38      0.30
01:59:46 PM dev120-96      1.01      8.08      0.00      8.00      0.01      9.00      9.00      0.91
01:59:46 PM dev120-97      1.01      8.08      0.00      8.00      0.01      9.00      9.00      0.91

In the above example “DEV” indicates the specific block device.

For example: “dev53-1″ means a block device with 53 as major number, and 1 as minor number.

The device name (DEV column) can display the actual device name (for example: sda, sda1, sdb1 etc.,), if you use the -p option (pretty print) as shown below.

$ sar -p -d 1 1
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:59:45 PM       DEV       tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util
01:59:46 PM       sda      1.01      0.00      0.00      0.00      0.00      4.00      1.00      0.10
01:59:46 PM      sda1      1.01      0.00      0.00      0.00      0.00      4.00      1.00      0.10
01:59:46 PM      sdb1      3.03     64.65      0.00     21.33      0.03      9.33      5.33      1.62
01:59:46 PM      sdc1      3.03     64.65      0.00     21.33      0.03      9.33      5.33      1.62
01:59:46 PM      sde1      8.08      0.00    105.05     13.00      0.00      0.38      0.38      0.30
01:59:46 PM      sdf1      8.08      0.00    105.05     13.00      0.00      0.38      0.38      0.30
01:59:46 PM      sda2      1.01      8.08      0.00      8.00      0.01      9.00      9.00      0.91
01:59:46 PM      sdb2      1.01      8.08      0.00      8.00      0.01      9.00      9.00      0.91

Following are few variations:

• sar -d
• sar -d 1 3
• sar -d -f /var/log/sa/sa10
• sar -p -d

7. Display context switch per second (sar -w)

This reports the total number of processes created per second, and total number of context switches per second. “1 3″ reports for every 1 seconds a total of 3 times.

$ sar -w 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

08:32:24 AM    proc/s   cswch/s
08:32:25 AM      3.00     53.00
08:32:26 AM      4.00     61.39
08:32:27 AM      2.00     57.00

Following are few variations:

• sar -w
• sar -w 1 3
• sar -w -f /var/log/sa/sa10

8. Reports run queue and load average (sar -q)

This reports the run queue size and load average of last 1 minute, 5 minutes, and 15 minutes. “1 3″ reports for every 1 seconds a total of 3 times.

$ sar -q 1 3
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

06:28:53 AM   runq-sz  plist-sz   ldavg-1   ldavg-5  ldavg-15   blocked
06:28:54 AM         0       230      2.00      3.00      5.00         0
06:28:55 AM         2       210      2.01      3.15      5.15         0
06:28:56 AM         2       230      2.12      3.12      5.12         0
Average:            3       230      3.12      3.12      5.12         0

Note: The “blocked” column displays the number of tasks that are currently blocked and waiting for I/O operation to complete.

Following are few variations:

• sar -q
• sar -q 1 3
• sar -q -f /var/log/sa/sa10

9. Report network statistics (sar -n)

This reports various network statistics. For example: number of packets received (transmitted) through the network card, statistics of packet failure etc.,. “1 3″ reports for every 1 seconds a total of 3 times.

sar -n KEYWORD

KEYWORD can be one of the following:

• DEV – Displays network devices vital statistics for eth0, eth1, etc.,
• EDEV – Display network device failure statistics
• NFS – Displays NFS client activities
• NFSD – Displays NFS server activities
• SOCK – Displays sockets in use for IPv4
• IP – Displays IPv4 network traffic
• EIP – Displays IPv4 network errors
• ICMP – Displays ICMPv4 network traffic
• EICMP – Displays ICMPv4 network errors
• TCP – Displays TCPv4 network traffic
• ETCP – Displays TCPv4 network errors
• UDP – Displays UDPv4 network traffic
• SOCK6, IP6, EIP6, ICMP6, UDP6 are for IPv6
• ALL – This displays all of the above information. The output will be very long.

$ sar -n DEV 1 1
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

01:11:13 PM     IFACE   rxpck/s   txpck/s   rxbyt/s   txbyt/s   rxcmp/s   txcmp/s  rxmcst/s
01:11:14 PM        lo      0.00      0.00      0.00      0.00      0.00      0.00      0.00
01:11:14 PM      eth0    342.57    342.57  93923.76 141773.27      0.00      0.00      0.00
01:11:14 PM      eth1      0.00      0.00      0.00      0.00      0.00      0.00      0.00

10. Report Sar Data Using Start Time (sar -s)

When you view historic sar data from the /var/log/sa/saXX file using “sar -f” option, it displays all the sar data for that specific day starting from 12:00 a.m for that day.

Using “-s hh:mi:ss” option, you can specify the start time. For example, if you specify “sar -s 10:00:00″, it will display the sar data starting from 10 a.m (instead of starting from midnight) as shown below.

You can combine -s option with other sar option.

For example, to report the load average on 26th of this month starting from 10 a.m in the morning, combine the -q and -s option as shown below.

$ sar -q -f /var/log/sa/sa23 -s 10:00:01
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

10:00:01 AM   runq-sz  plist-sz   ldavg-1   ldavg-5  ldavg-15   blocked
10:10:01 AM         0       127      2.00      3.00      5.00         0
10:20:01 AM         0       127      2.00      3.00      5.00         0
...
11:20:01 AM         0       127      5.00      3.00      3.00         0
12:00:01 PM         0       127      4.00      2.00      1.00         0

There is no option to limit the end-time. You just have to get creative and use head command as shown below.

For example, starting from 10 a.m, if you want to see 7 entries, you have to pipe the above output to “head -n 10″.

$ sar -q -f /var/log/sa/sa23 -s 10:00:01 | head -n 10
Linux 2.6.18-194.el5PAE (dev-db)        03/26/2011      _i686_  (8 CPU)

10:00:01 AM   runq-sz  plist-sz   ldavg-1   ldavg-5  ldavg-15   blocked
10:10:01 AM         0       127      2.00      3.00      5.00         0
10:20:01 AM         0       127      2.00      3.00      5.00         0
10:30:01 AM         0       127      3.00      5.00      2.00         0
10:40:01 AM         0       127      4.00      2.00      1.00         2
10:50:01 AM         0       127      3.00      5.00      5.00         0
11:00:01 AM         0       127      2.00      1.00      6.00         0
11:10:01 AM         0       127      1.00      3.00      7.00         2