| <div class="docbook"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">8.4. Connection Limit Providers</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="Java-Broker-Security-AccessControlProviders.html">Prev</a> </td><th width="60%" align="center">Chapter 8. Security</th><td width="20%" align="right"> <a accesskey="n" href="Java-Broker-Security-Configuration-Encryption.html">Next</a></td></tr></table><hr /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="Java-Broker-Security-ConnectionLimitProviders"></a>8.4. Connection Limit Providers</h2></div></div></div><p> | |
| The Connection Limit Provider governs the limits of connections that an user can simultaneously open. | |
| </p><p>There are two points within the hierarchy that enforce connection limits: the Broker itself and at each | |
| Virtual Host. When a limit needs to be checked, every check point configured with a provider is consulted | |
| for a decision. The example, when making a decision about the opening a new connection. If the Virtual Host is | |
| configured with Connection Limit Provider then the limits are checked. Unless the connection is rejected, | |
| the decision is delegated to the Connection Limit Provider configured at the Broker. | |
| </p><p>Connection Limit Provider is configured with a set of CLT (connection limit) rules. The rules determine | |
| the limit of open connections, how many connections can user open on the | |
| <a class="link" href="Java-Broker-Concepts-Ports.html" title="4.8. Ports">AMQP Ports</a>. | |
| </p><p> | |
| CLT rules may be written in terms of user or group names. A rule written in terms of a group name applies to the | |
| user if he is a member of that group. Groups information is obtained from the | |
| <a class="link" href="Java-Broker-Security.html#Java-Broker-Security-Authentication-Providers" title="8.1. Authentication Providers">Authentication Providers</a> | |
| and <a class="link" href="Java-Broker-Security-Group-Providers.html" title="8.2. Group Providers">Group Providers</a>. Writing CLT rules in terms of | |
| user names is recommended. | |
| </p><p> | |
| The Connection Limit Providers can be configured using | |
| <a class="link" href="Java-Broker-Management-Channel-REST-API.html" title="6.3. REST API">REST Management interfaces</a> | |
| and <a class="link" href="Java-Broker-Management-Channel-Web-Console.html" title="6.2. Web Management Console">Web Management Console</a>. | |
| </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="Java-Broker-Security-ConnectionLimitProviders-Types"></a>8.4.1. Types</h3></div></div></div><p>There are currently two types of Connection Limit Provider implementing CLT rules. | |
| </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> | |
| <span class="emphasis"><em>RulesBased</em></span> | |
| - a provider that stores the rule-set within the Broker's or VirtualHost's configuration. | |
| </p></li><li class="listitem"><p> | |
| </p><p> | |
| <span class="emphasis"><em>ConnectionLimitFile</em></span> | |
| - a provider that references an externally provided CLT file (or data url). | |
| </p><p> | |
| </p></li></ul></div><p> | |
| </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="Java-Broker-Security-ConnectionLimitProviders-Rules"></a>8.4.2. | |
| Connection Limit Rules | |
| </h3></div></div></div><p>An CLT rule is composed of an user or group identification, AMQP port name and connection limits. | |
| Let's look at some example. | |
| </p><pre class="programlisting"> | |
| # Limits simultaneously open connection by alice on brokerAmqp port up to 10. | |
| CLT alice port=brokerAmqp connection_count=10 | |
| </pre><p>If there is multiple rules for given user (or group) then the rules are merge into a single most | |
| restrictive rule. | |
| </p><pre class="programlisting"> | |
| CLT alice port=brokerAmqp connection_count=10 | |
| CLT alice port=brokerAmqp connection_count=12 connection_frequency_count=60/1m | |
| CLT alice port=brokerAmqp connection_frequency_count=100/1m | |
| </pre><p>The previous rules will be merge into a single effective rule.</p><pre class="programlisting"> | |
| CLT alice port=brokerAmqp connection_count=10 connection_frequency_count=60/1m | |
| </pre><p>The rules are applied in following order:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>The effective rule for given user.</p></li><li class="listitem"><p>The effective rule for given set of groups that user is a member of.</p></li><li class="listitem"><p>The default rule, a rule with the user ALL that matches any user.</p></li></ol></div><p>At the first broker looks for a rule for given user. If any rule is not found then broker will look for | |
| the group rules. If any group rule is not found then broker will look for a default rule. An user without | |
| any rule is not restricted. | |
| </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="Java-Broker-Security-ConnectionLimitProviders-Syntax"></a>8.4.3. | |
| Syntax | |
| </h3></div></div></div><p> | |
| Connection limit rules follow this syntax: | |
| </p><pre class="programlisting"> | |
| CLT {<user-name>|<group-name>|ALL} [BLOCK] [port=<AMQP-port-name>|ALL] [property="<property-value>"] | |
| </pre><p> | |
| A rule with user name ALL is default rule. Likewise a rule with port=ALL is applied to all ports. | |
| The parameter BLOCK is optional and marks user or group that is not allowed to connect on the port. | |
| </p><p> | |
| Comments may be introduced with the hash (#) character and are ignored. A line can be broken with the slash | |
| (\) character. | |
| </p><pre class="programlisting"> | |
| # A comment | |
| CLT alice port=brokerAMQP connection_limit=10 # Also a comment | |
| CLT mark port=brokerAMQP \ # A broken line | |
| connection_limit=10 \ | |
| connection_frequency_limit=60/1m | |
| CLT ALL BLOCK # A default rule | |
| </pre><div class="table"><a id="table-Java-Broker-Security-ConnectionLimitProviders-Syntax_properties"></a><p class="title"><strong>Table 8.6. List of connection limit (CLT) properties</strong></p><div class="table-contents"><table summary="List of connection limit (CLT) properties" border="1"><colgroup><col class="name" /><col class="description" /></colgroup><tbody><tr><td> | |
| <span class="command"><strong>connection_limit</strong></span> | |
| </td><td> | |
| <p> | |
| Integer. A maximum number of connections the messaging user can establish to the Virtual | |
| Host on AMQP port. | |
| </p> | |
| <p> | |
| Alternatives: connection-limit, connectionLimit. | |
| </p> | |
| </td></tr><tr><td> | |
| <span class="command"><strong>connection_frequency_limit</strong></span> | |
| </td><td> | |
| <p> | |
| A maximum number of connections the messaging user can establish to the Virtual Host | |
| on AMQP port within defined period of time, which is 1 minute by default. | |
| The connection frequency limit is specified in the format: limit/period, where time | |
| period is written as xHyMz.wS - x hours, y minutes and z.w seconds. | |
| </p> | |
| <p> | |
| In case of time period 1 hour/minute/second the digit 1 can be omitted, | |
| for example: 7200/H or 120/M or 2/S. | |
| (7200/H is not the same frequency limit as 120/H or 2/S). | |
| </p> | |
| <p> | |
| If the period is omitted then the default frequency period is used. | |
| If required, the default frequency period can be changed using CONFIG command. | |
| See an example below. Setting it to zero or negative value turns off the connection | |
| frequency evaluation. | |
| </p> | |
| <p> | |
| Alternatives: connection-frequency-limit, connectionFrequencyLimit. | |
| </p> | |
| </td></tr><tr><td> | |
| <span class="command"><strong>port</strong></span> | |
| </td><td> | |
| <p> | |
| String. The AMQP port name, ALL is the default value. | |
| </p> | |
| </td></tr></tbody></table></div></div><br class="table-break" /><p> | |
| The default time period for frequency limit can be set up with the <code class="literal">CONFIG</code> command. | |
| Default frequency period is specified in ms. | |
| </p><pre class="programlisting"> | |
| CONFIG default_frequency_period=60000 | |
| </pre><p> | |
| default-frequency-period and defaultFrequencyPeriod are valid alternatives to the default_frequency_period. | |
| </p><p> | |
| The default frequency period may be specified as context variable | |
| <code class="literal">qpid.broker.connectionLimiter.frequencyPeriodInMillis</code>. | |
| </p><p> | |
| The Broker logs rejected connections when an user breaks the limit. But the Broker could also log | |
| the accepted connections with current counter value. The full logging could be turn on with | |
| <code class="literal">CONFIG</code> command. | |
| </p><pre class="programlisting"> | |
| CONFIG log_all=true default_frequency_period=60000 | |
| </pre><p> | |
| log-all and logAll are valid alternatives to the log_all. | |
| </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="Java-Broker-Security-ConnectionLimitProviders-WorkedExample"></a>8.4.4. | |
| Worked Example | |
| </h3></div></div></div><p> | |
| Here are some example of connection limits illustrating common use cases. | |
| </p><p> | |
| Suppose you wish to restrict two users: a user <code class="literal">operator</code> can establish at the most 50 | |
| connections on any port. A user <code class="literal">publisher</code> can establish 30 new connection per two minutes | |
| but at the most 20 parallel connections on <code class="literal">amqp</code> port. Another users should be blocked. | |
| </p><div class="example"><a id="d0e8463"></a><p class="title"><strong>Example 8.6. CLT file example</strong></p><div class="example-contents"><pre class="programlisting"> | |
| # Limit operator | |
| CLT operator connection_limit=50 | |
| # Limit publisher | |
| CLT publisher port=amqp connection_frequency_limit=30/2M connection_limit=20 | |
| # Block all users by default | |
| CLT ALL BLOCK | |
| </pre></div></div><br class="example-break" /></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="Java-Broker-Security-AccessControlProviders.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="Java-Broker-Security.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="Java-Broker-Security-Configuration-Encryption.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">8.3. Access Control Providers </td><td width="20%" align="center"><a accesskey="h" href="Apache-Qpid-Broker-J-Book.html">Home</a></td><td width="40%" align="right" valign="top"> 8.5. Configuration Encryption</td></tr></table></div></div> |