[root@localhost ttt]# yum install httpd-tools
Loaded plugins: fastestmirror
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* extras: mirrors.163.com
* updates: mirrors.163.com
Resolving Dependencies
--> Running transaction check
---> Package httpd-tools.x86_64 0:2.4.6-40.el7.centos.4 will be installed
--> Processing Dependency: libaprutil-1.so.0()(64bit) for package: httpd-tools-2.4.6-40.el7.centos.4.x86_64
--> Processing Dependency: libapr-1.so.0()(64bit) for package: httpd-tools-2.4.6-40.el7.centos.4.x86_64
--> Running transaction check
---> Package apr.x86_64 0:1.4.8-3.el7 will be installed
---> Package apr-util.x86_64 0:1.5.2-6.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=====================================================================================================================================
Package Arch Version Repository Size
=====================================================================================================================================
Installing: httpd-tools x86_64 2.4.6-40.el7.centos.4 updates 83 k
Installing for dependencies:apr x86_64 1.4.8-3.el7 base 103 k
apr-util x86_64 1.5.2-6.el7 base 92 k

Transaction Summary
====================================================================================================================================
Install 1 Package (+2 Dependent packages)

Total download size: 278 k
Installed size: 584 k
Is this ok [y/d/N]: y
Downloading packages:
(1/3): httpd-tools-2.4.6-40.el7.centos.4.x86_64.rpm | 83 kB 00:00:00
(2/3): apr-1.4.8-3.el7.x86_64.rpm                   | 103 kB 00:00:00
(3/3): apr-util-1.5.2-6.el7.x86_64.rpm              | 92 kB 00:00:00
------------------------------------------------------------------------------------------------------------------------------------
Total 203 kB/s | 278 kB 00:00:01
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : apr-1.4.8-3.el7.x86_64 1/3
Installing : apr-util-1.5.2-6.el7.x86_64 2/3
Installing : httpd-tools-2.4.6-40.el7.centos.4.x86_64 3/3
Verifying : httpd-tools-2.4.6-40.el7.centos.4.x86_64 1/3
Verifying : apr-util-1.5.2-6.el7.x86_64 2/3
Verifying : apr-1.4.8-3.el7.x86_64 3/3

Installed:
httpd-tools.x86_64 0:2.4.6-40.el7.centos.4

Dependency Installed:
apr.x86_64 0:1.4.8-3.el7 apr-util.x86_64 0:1.5.2-6.el7

Complete!

ab: wrong number of arguments
Usage: ab [options] [http[s]://]hostname[:port]/path
Options are:
    -n requests     Number of requests to perform
    -c concurrency  Number of multiple requests to make at a time
    -t timelimit    Seconds to max. to spend on benchmarking
                    This implies -n 50000
    -s timeout      Seconds to max. wait for each response
                    Default is 30 seconds
    -b windowsize   Size of TCP send/receive buffer, in bytes
    -B address      Address to bind to when making outgoing connections
    -p postfile     File containing data to POST. Remember also to set -T
    -u putfile      File containing data to PUT. Remember also to set -T
    -T content-type Content-type header to use for POST/PUT data, eg.
                    ‘application/x-www-form-urlencoded‘
                    Default is ‘text/plain‘
    -v verbosity    How much troubleshooting info to print
    -w              Print out results in HTML tables
    -i              Use HEAD instead of GET
    -x attributes   String to insert as table attributes
    -y attributes   String to insert as tr attributes
    -z attributes   String to insert as td or th attributes
    -C attribute    Add cookie, eg. ‘Apache=1234‘. (repeatable)
    -H attribute    Add Arbitrary header line, eg. ‘Accept-Encoding: gzip‘
                    Inserted after all normal header lines. (repeatable)
    -A attribute    Add Basic WWW Authentication, the attributes
                    are a colon separated username and password.
    -P attribute    Add Basic Proxy Authentication, the attributes
                    are a colon separated username and password.
    -X proxy:port   Proxyserver and port number to use
    -V              Print version number and exit
    -k              Use HTTP KeepAlive feature
    -d              Do not show percentiles served table.
    -S              Do not show confidence estimators and warnings.
    -q              Do not show progress when doing more than 150 requests
    -g filename     Output collected data to gnuplot format file.
    -e filename     Output CSV file with percentages served
    -r              Don‘t exit on socket receive errors.
    -h              Display usage information (this message)
    -Z ciphersuite  Specify SSL/TLS cipher suite (See openssl ciphers)
    -f protocol     Specify SSL/TLS protocol
                    (SSL2, SSL3, TLS1, TLS1.1, TLS1.2 or ALL)