<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="traffic_replay.7">

<refmeta>
	<refentrytitle>traffic_replay</refentrytitle>
	<manvolnum>7</manvolnum>
	<refmiscinfo class="source">Samba</refmiscinfo>
	<refmiscinfo class="manual">User Commands</refmiscinfo>
	<refmiscinfo class="version">&doc.version;</refmiscinfo>
</refmeta>


<refnamediv>
	<refname>traffic_replay</refname>
	<refpurpose>Samba traffic generation tool.
	</refpurpose>
</refnamediv>

<refsynopsisdiv>
	<cmdsynopsis>
		<command>traffic_replay</command>
		<arg choice="opt">-F, --fixed-password &lt;test-password&gt;</arg>
		<arg choice="opt">-S, --scale-traffic &lt;scale by factor&gt;</arg>
		<arg choice="opt">-r, --replay-rate &lt;scale by factor&gt;</arg>
		<arg choice="opt">-D, --duration &lt;seconds&gt;</arg>
		<arg choice="opt">--traffic-summary &lt;output file&gt;</arg>
		<arg choice="opt">-I, --instance-id &lt;id&gt;</arg>
		<arg choice="opt">-K, --prefer-kerberos</arg>
		<arg choice="opt">-B, --badpassword-frequency &lt;frequency&gt;</arg>
		<arg choice="opt">--dns-rate &lt;rate&gt;</arg>
		<arg choice="opt">-t, --timing-data &lt;file&gt;</arg>
		<arg choice="opt">--random-seed &lt;seed&gt;</arg>
		<arg choice="opt">-U, --username user</arg>
		<arg choice="opt">--password &lt;password&gt;</arg>
		<arg choice="opt">-W --workgroup &lt;workgroup&gt;</arg>
		<arg choice="opt">--realm &lt;realm&gt;</arg>
		<arg choice="opt">-s, --config-file &lt;file&gt;</arg>
		<arg choice="opt">-k, --kerberos &lt;kerberos&gt;</arg>
		<arg choice="opt">--ipaddress &lt;address&gt;</arg>
		<arg choice="opt">-P, --machine-pass</arg>
		<arg choice="opt">--option &lt;option&gt;</arg>
		<arg choice="opt">-d, --debuglevel &lt;debug level&gt;</arg>
		<arg choice="req">summary-file</arg>
		<arg choice="req">dns-hostname</arg>
	</cmdsynopsis>

	<cmdsynopsis>
		<command>traffic_replay</command>
		<arg choice="opt">-G, --generate-users-only</arg>
		<arg choice="opt">-F, --fixed-password &lt;test-password&gt;</arg>
		<arg choice="opt">-n, --number-of-users &lt;total users&gt;</arg>
		<arg choice="opt">--number-of-groups &lt;total groups&gt;</arg>
		<arg choice="opt">--average-groups-per-user &lt;average number&gt;</arg>
		<arg choice="opt">--group-memberships &lt;total memberships&gt;</arg>
		<arg choice="req">dns-hostname</arg>
	</cmdsynopsis>

	<cmdsynopsis>
		<command>traffic_replay</command>
		<arg choice="req">-c|--clean-up</arg>
		<arg choice="req">dns-hostname</arg>
	</cmdsynopsis>

	<cmdsynopsis>
		<command>traffic_replay</command>
		<arg choice="opt">-h, --help</arg>
		<arg choice="opt">-V, --version</arg>
	</cmdsynopsis>
</refsynopsisdiv>

<refsect1>
	<title>DESCRIPTION</title>
	<para>This tool is part of the <citerefentry><refentrytitle>samba</refentrytitle>
	<manvolnum>7</manvolnum></citerefentry> suite.</para>
	<para>This tool generates traffic in order to measure the performance
	of a Samba DC, and to test how well Samba will scale as a network
	increases in size. It can simulate multiple different hosts making
	multiple different types of requests to a DC.</para>

	<para>This tool is intended to run against a dedicated test DC (rather
	than a live DC that is handling real network traffic).</para>

	<para>Note that a side-effect of running this tool is that user
	accounts will be created on the DC, in order to test various Samba
	operations. As creating accounts can be very time-consuming, these
	users will remain on the DC by default. To remove these accounts, use
	the --clean-up option.
	</para>
</refsect1>

<refsect1>
	<title>OPTIONS</title>

	<variablelist>

	<varlistentry>
	<term>-h|--help</term>
	<listitem><para>
	Print a summary of command line options.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>summary-file</term>
	<listitem><para>
	File containing the network traffic to replay. This should either be
	a traffic-summary (generated by <command>traffic_summary.pl</command>)
	or a traffic-model (generated by <command>traffic_learner</command>).
	Based on this file, this tool will generate 'conversations' which
	represent Samba activity between a network host and the DC.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>dns-hostname</term>
	<listitem><para>
	The full DNS hostname of the DC that's being tested. The Samba activity
	in the summary-file will be replicated and directed at this DC. It's
	recommended that you use a dedicated DC for testing and don't try to run
	this tool against a DC that's processing live network traffic.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>-F|--fixed-password &lt;test-password&gt;</term>
	<listitem><para>
	Test users are created when this tool is run, so that actual Samba
	activity, such as authorizing users, can be mimicked. This option
	specifies the password that will be used for any test users that are
	created.</para>

	<para>Note that any users created by this tool will remain on the DC
	until you run the --clean-up option. Therefore, the fixed-password
	option needs to be the same each time the tool is run, otherwise the
	test users won't authenticate correctly.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>random-seed</term>
	<listitem><para>
	A number to seed the random number generator with. When traffic is
	generated from a model-file, use this option to keep the traffic
	consistent across multiple test runs. This allows you to compare the
	performance of Samba between different releases.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>Traffic Model Options</term>
	<listitem><para>
	When the summary-file is a traffic-model (produced by
	<command>traffic_learner</command>), use these options to alter the
	traffic that gets generated.</para>
	<itemizedlist>
		<varlistentry>
		<term>-D|--duration &lt;seconds&gt;</term>
		<listitem><para>
		Specifies the approximate duration in seconds to generate
		traffic for. The default is 60 seconds.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>-r|--replay-rate &lt;factor&gt;</term>
		<listitem><para>
		Replays the traffic faster by this factor. This option won't
		affect the number of conversations (which is based on the
		traffic model), but the rate at which the packets are sent will
		be increased.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>-S|--scale-traffic &lt;factor&gt;</term>
		<listitem><para>
		Increases the number of conversations by this factor. This
		option won't affect the rate at which packets get sent (which
		is still based on the traffic model), but it will mean more
		conversations get replayed.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>--traffic-summary &lt;output-file&gt;</term>
		<listitem><para>
		Instead of replaying a traffic-model, this option generates a
		traffic-summary file based on what traffic would be sent. Using
		a traffic-model allows you to scale the packet rate and number
		of packets sent. However, using a traffic-model introduces
		some randomness into the traffic generation. So running the
		same traffic_replay command multiple times using a model file
		may result in some differences in the actual traffic sent.
		However, running the same traffic_replay command multiple times
		with a traffic-summary file will always result in the same
		traffic being sent. </para>
		<para>
		For taking performance measurements over several test runs,
		it's recommended to use this option and replay the traffic from
		a traffic-summary file, or to use the --random-seed option.
		</para></listitem>
		</varlistentry>
	</itemizedlist>
	</listitem>
	</varlistentry>

	<varlistentry>
	<term>--generate-users-only</term>
	<listitem><para>Add extra user/groups on the DC to increase the DB
	size. By default, this tool automatically creates test users that map
	to the traffic conversations being generated. This option allows extra
	users to be created on top of this. Note that these extra users may
	not actually used for traffic generation - the traffic generation is
	still based on the number of conversations from the model/summary file.
	</para>
	
	<para>
	Generating a large number of users can take a long time, so it this
	option allows this to be done only once.</para>

	<para>Note that the users created will remain on the DC until the
	tool is run with the --clean-up option. This means that it is best to
	only assign group memberships once, i.e. run --clean-up before
	assigning a different allocation of group memberships.</para>
	<itemizedlist>

		<varlistentry>
		<term>-n|--number-of-users &lt;total-users&gt;</term>
		<listitem><para>
		Specifies the total number of test users to create (excluding
		any machine accounts required for the traffic). Note that these
		extra users simply populate the DC's DB - the actual user
		traffic generated is still based on the summary-file.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>--number-of-groups &lt;total-groups&gt;</term>
		<listitem><para>
		Creates the specified number of groups, for assigning the test
		users to. Note that users are not automatically assigned to
		groups - use either --average-groups-per-user or
		--group-membership to do this.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>--average-groups-per-user &lt;average-groups&gt;</term>
		<listitem><para>
		Randomly assigns the test users to the test groups created.
		The group memberships are distributed so that the overall
		average groups that a user is member of matches this number.
		Some users will belong to more groups and some users will
		belong to fewer groups. This option is incompatible with
		the --group-membership option.
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>--group-memberships &lt;total-memberships&gt;</term>
		<listitem><para>
		Randomly assigns the test users to the test groups created.
		The group memberships are distributed so that the total
		groups that a user is member of, across all users, matches
		this number. For example, with 100 users and 10 groups,
		--group-memberships=300 would assign a user to 3 groups
		on average. Some users will belong to more groups and some
		users will belong to fewer groups, but the total of all
		member linked attributes would be 300. This option is
		incompatible with the --group-membership option.
		</para></listitem>
		</varlistentry>
	</itemizedlist>
	</listitem>
	</varlistentry>

	<varlistentry>
	<term>--clean-up</term>
	<listitem><para>
	Cleans up any users and groups that were created by previously running
	this tool. It is recommended you always clean up after running the tool.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>-I|--instance-id &lt;id&gt;</term>
	<listitem><para>
	Use this option to run multiple instances of the tool on the same DC at
	the same time. This adds a prefix to the test users generated to keep
	them separate on the DC.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>-K|--prefer-kerberos</term>
	<listitem><para>
	Use Kerberos to authenticate the test users.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>-B|--badpassword-frequency &lt;frequency&gt;</term>
	<listitem><para>
	Use this option to simulate users trying to authenticate with an
	incorrect password.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>--dns-rate &lt;rate&gt;</term>
	<listitem><para>
	Increase the rate at which DNS packets get sent.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>-t|--timing-data &lt;file&gt;</term>
	<listitem><para>
	This writes extra timing data to the file specified. This is mostly
	used for reporting options, such as generating graphs.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term>Samba Common Options</term>
	<listitem>
	<itemizedlist>
		&stdarg.client.debug;
		&stdarg.configfile;
		&stdarg.option;
		<varlistentry>
		<term>--realm=REALM</term>
		<listitem><para>
		Set the realm name
		</para></listitem>
		</varlistentry>
		&stdarg.version;
	</itemizedlist>
	</listitem>
	</varlistentry>

	<varlistentry>
	<term>Credential Options</term>
	<listitem>
	<itemizedlist>
		<varlistentry>
		<term>--simple-bind-dn=DN</term>
		<listitem><para>
		DN to use for a simple bind
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>--password=PASSWORD</term>
		<listitem><para>
		Password
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>-U USERNAME|--username=USERNAME</term>
		<listitem><para>
		Username
		</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>-W WORKGROUP|--workgroup=WORKGROUP</term>
		<listitem><para>
		Workgroup
		</para></listitem>
		</varlistentry>

		&stdarg.kerberos;

		<varlistentry>
		<term>--ipaddress=IPADDRESS</term>
		<listitem><para>
		IP address of the server
		</para></listitem>
		</varlistentry>

		&stdarg.machinepass;
	</itemizedlist>
	</listitem>
	</varlistentry>

	</variablelist>
</refsect1>

<refsect1>
<title>OPERATIONS</title>

<refsect2>
	<title>Generating a traffic-summary file</title>
	<para>To use this tool, you need either a traffic-summary file or a
	traffic-model file. To generate either of these files, you will need a
	packet capture of actual Samba activity on your network.</para>

	<para>Use Wireshark to take a packet capture on your network of the
	traffic you want to generate. For example, if you want to simulate lots
	of users logging on, then take a capture at 8:30am when users are
	logging in.</para>

	<para>Next, you need to convert your packet capture into a traffic
	summary file, using <command>traffic_summary.pl</command>. Basically
	this removes any sensitive information from the capture and summarizes
	what type of packet was sent and when.</para>

	<para>Refer to the <command>traffic_summary.pl --help</command> help for more
	details, but the basic command will look something like:</para>

	<para><command>tshark -r capture.pcapng -T pdml |
	traffic_summary.pl &gt; traffic-summary.txt</command></para>
</refsect2>

<refsect2>
	<title>Replaying a traffic-summary file</title>
	<para>Once you have a traffic-summary file, you can use it to generate
	traffic. The traffic_replay tool gets passed the traffic-summary file,
	along with the full DNS hostname of the DC being tested. You also need
	to provide some user credentials, and possibly the Samba realm and
	workgroup (although the realm and workgroup may be determined
	automatically, for example from the /etc/smb.conf file, if one is 
	present). E.g.</para>

	<para><command>traffic_replay traffic-summary.txt
	my-dc.samdom.example.com -UAdmin%password -W samdom
	--realm=samdom.example.com --fixed-password=blahblah123!</command>
	</para>

	<para>This simply regenerates Samba activity seen in the traffic
	summary. The traffic is grouped into 'conversations' between a host and
	the DC.	A user and machine account is created on the DC for each
	conversation, in order to allow logon and other operations to succeed.
	The script generates the same types of packets as those seen in the
	summary.</para>

	<para>Creating users can be quite a time-consuming process, especially
	if a lot of conversations are being generated. To save time, the test
	users remain on the DC by default. You will need to run the --clean-up
	option to remove them, once you have finished generating traffic.
	Because the same test users are used across multiple runs of the tool,
	a consistent password for these users needs to be used - this is
	specified by the --fixed-password option.
	</para>

	<para>The benefit of this tool over simply using tcprelay is that the
	traffic generated is independent of any specific network. No setup is
	needed beforehand on the test DC. The traffic no longer contains
	sensitive details, so the traffic summary could be potentially shared
	with other Samba developers.</para>

	<para>However, replaying a traffic-summary directly is somewhat limited
	in what you can actually do. A more flexible approach is to generate
	the traffic using a model file.</para>
</refsect2>

<refsect2>
	<title>Generating a traffic-model file</title>
	<para>To create a traffic-model file, simply pass the traffic-summary
	file to the <command>traffic_learner</command> script. E.g.</para>

	<para><command>traffic_learner traffic-summary.txt
	-o traffic-model.txt</command></para>

	<para>This generates a model of the Samba activity in your network.
	This model-file can now be used to generate traffic.</para>
</refsect2>

<refsect2>
	<title>Replaying the traffic-model file</title>
	<para>Packet generation using a traffic-model file uses the same
	command as a traffic-summary file, e.g.</para>

	<para><command>traffic_replay traffic-model.txt
	my-dc.samdom.example.com -UAdmin%password</command>
	</para>

	<para>By default, this will generate 60 seconds worth of traffic based
	on the model. You can specify longer using the --duration parameter.
	</para>

	<para>The traffic generated is an approximation of what was seen in
	the network capture. The traffic generation involves some randomness,
	so running the same command multiple times may result in slightly
	different traffic being generated (although you can avoid this, by
	specifying the --random-seed option).</para>

	<para>As well as changing how long the model runs for, you can also
	change how many conversations get generated and how fast the traffic
	gets replayed. To roughly double the number of conversations that get
	replayed, use --scale-traffic=2 or to approximately halve the number
	use --scale-traffic=0.5. To approximately double how quickly the
	conversations get replayed, use --replay-rate=2, or to halve this use
	--replay-rate=0.5</para>

	<para>For example, to generate approximately 10 times the amount of
	traffic seen over a two-minute period (based on the network capture),
	use:</para>

	<para><command>traffic_replay traffic-model.txt
	my-dc.samdom.example.com -UAdmin%password --fixed-password=blahblah123!
	--scale-traffic=10 --duration=120</command></para>
</refsect2>

<refsect2>
	<title>Scaling the number of users</title>
	<para>The performance of a Samba DC running a small subset of test
	users will be different to a fully-populated Samba DC running in a
	network. As the number of users increases, the size of the DB
	increases, and a very large DB will perform worse than a smaller DB.
	</para>

	<para>To increase the size of the Samba DB, this tool can also create
	extra users and groups. These extra users are basically 'filler' for
	the DB. They won't actually be used to generate traffic, but they may
	slow down authentication of the test users.</para>

	<para>For example, to populate the DB with an extra 5000 users (note
	this will take a while), use the command:</para>

	<para><command>traffic_replay my-dc.samdom.example.com
	-UAdmin%password --generate-users-only --fixed-password=blahblah123!
	--number-of-users=5000</command></para>

	<para>You can also create groups and assign users to groups. The users
	can be randomly assigned to groups - this includes any extra users
	created as well as the users that map to conversations. Use either
	--average-groups-per-user or --group-memberships to specify how many
	group memberships should be assigned to the test users.</para>

	<para>For example, to assign the users in the replayed conversations
	into 10 groups on average, use a command like:</para>

	<para><command>traffic_replay traffic-model.txt my-dc.samdom.example.com
	-UAdmin%password --fixed-password=blahblah123!
	--generate-users-only --number-of-groups=25 --average-groups-per-user=10
	</command></para>

	<para>The users created by the test will have names like STGU-0-xyz.
	The groups generated have names like STGG-0-xyz.</para>
</refsect2>
</refsect1>


<refsect1>
	<title>VERSION</title>

	<para>This man page is complete for version &doc.version; of the Samba
	suite.</para>
</refsect1>

<refsect1>
	<title>SEE ALSO</title>
	<para>
	<citerefentry>
	<refentrytitle>traffic_learner</refentrytitle><manvolnum>7</manvolnum>
	</citerefentry>.
	</para>
</refsect1>

<refsect1>
	<title>AUTHOR</title>

	<para>The original Samba software and related utilities
	were created by Andrew Tridgell. Samba is now developed
	by the Samba Team as an Open Source project similar
	to the way the Linux kernel is developed.</para>

	<para>The traffic_replay tool was developed by the Samba team at
	Catalyst IT Ltd.</para>

	<para>The traffic_replay manpage was written by Tim Beale.</para>
</refsect1>

</refentry>