Provided by: tntnet_2.2.1-4build1_amd64 
NAME
tntnet.xml - configuration file for tntnet(8)
DESCRIPTION
Tntnet is configured using a xml file. The name of the file is tntnet.xml. The root node
of tntnet.xml should be tntnet while it is not checked. Most of the settings are just
single values. They are described here in alphabetical order.
SETTINGS
This section describes the variables, used by Tntnet (8).
<accessLog>filename</accessLog>
Writes a log entry for each request in a common format. This format is compatible
with most log file analyze systems for http servers.
The log file has the fields: peer-ip - username [time] "http-method query-string
HTTP/major-version.minor-version" http-return-code content-size "referer" "user-
agent"
The username, referer and user-agent may be '-' when the value is not available.
Also the content-size can be empty in some cases.
Example
<accessLog>/var/log/tntnet/access.log</accessLog
<bufferSize>bytes</bufferSize>
Specifies the number of bytes sent in a single system-call. This does not limit
anything in application-level. It does not affect e.g. savepoints or
exception-handling. Component-output is collected completely and then passed in
chunks of bufferSize bytes to the operating system.
The default value is 16384.
<compPath> [ <entry>path1</entry> ] </compPath>
compPath specifies, where tntnet should search for webapplications. Tntnet searches
first in the current directory and then in each directory, you specify here, until
a library is found. You can repeat the directive as many times as desired to add
more entries. If it is not found, the next mappings entry is tried.
Example
<compPath>
<entry>/usr/local/lib/tntnet</entry>
<entry>/usr/local/share/tntnet</entry>
</compPath>
<chroot>directory</chroot>
Does a chroot(2)-system call on startup, which locks the process into the directory
at system-level.
Example
<chroot>/var/tntnet</chroot>
<daemon>0|1</daemon>
If this flag is set to 1, Tntnet forks at startup and terminates the parent-process
on successful initialization.
<dir>directory</dir>
Changes the current working directory of the process on startup.
Example
<dir>/var/tntnet</dir>
<enableCompression>yes|no</enableCompression>
Specifies, if Tntnet should use gzip-compression at http-level. By default Tntnet
use compression. A http-client like a web browser can send a header
"Accept-Encoding", to tell Tntnet, that it would accept compressed data. Tntnet
then can decide, if it use compression. When the body is complete, Tntnet tries to
compress the body. If the data can be compressed by more than 10%, Tntnet sends
this compressed data. With this flag, this feature can be turned off.
Compression slows down processing but reduces the network-load. Normally the size
of html-pages can be compressed by about 70%, while Tntnet slows down by up to 30%.
Example
<enableCompression>no</enableCompression>
<errorLog>filename</errorLog>
Redirects stderr to the specified file when tntnet runs as a daemon. If ErrorLog is
not set stderr is redirected to /dev/null.
Example
<errorLog>/var/log/tntnet/error.log</errorLog>
<group>unix-group-id</group>
Changes the group under which tntnet runs.
The user is changes using the system call setgid(2), which is only allowed, when
tntnet starts as root user.
Example
<group>tntnet-group</group>
<keepAliveTimeout>milliseconds</keepAliveTimeout>
Sets the timeout for keep-alive requests.
Tntnet tries to do keep-alive-requests wherever possible. This has the effect, that
tntnet can receive multiple requests within a single tcp-connection. The connection
times out after KeepAliveTimeout milliseconds. The timeout defaults to 15000ms.
Example
<keepAliveTimeout>300000</keepAliveTimeout>
<keepAliveMax>number</keepAliveMax>
Sets the maximum number of request per tcp-connection. This defaults to 100.
Example
<keepAliveTimeout>10</keepAliveTimeout>
<listeners>listener definition</listeners>
Specifies, on which local interfaces tntnet waits for connections. There can be
more than one Listen-directives, in which case tntnet waits on every address.
See separate section Listeners
<logging>listener definition</logging>
Configures logging. See separate section logging
<listenRetry>number</listenRetry>
On startup Tntnet calls listen on the specified port. When the systemcall returns
with an error, Tntnet tries again and fails after the specified number of attempts.
The default number is 5.
Example
<listenRetry>10</listenRetry>
<listenBacklog>number</listenBacklog>
The system-call listen(3p) needs a parameter backlog, which specifies, how many
pending connections the operating-system should queue before it starts to ignore
new request. The value is configurable here.
The default value is 16.
Example
<ListenBacklog>64</ListenBacklog>
<mappings>urlmappings</mappings>
This is the most important setting for tntnet. It specifies, which components
schould be called on which urls.
For details see the section Url mapping.
<maxUrlMapCache>number</maxUrlMapCache>
Mapping urls to components is done using regular expressions. Executing these
expressions is quite expensive while the number of different urls is quite limited
in typical web applications. Hence tntnet caches the results.
The caching algorithm is very simple. Tntnet just collects the results in a map.
When the maximum size of the list is reached, it is cleared. This makes management
of the cache very cheap.
This setting sets the maximum number of entries in the map.
If you see frequently a warning message, that the cache is cleared, you may
consider increasing the size.
The default value is 8192.
Example
<maxUrlMapCache>32768</maxUrlMapCache>
<maxRequestSize>number</maxRequestSize>
This directive limits the size of the request. After number Bytes the connection is
just closed. This prevents denial-of-service-attacks through long requests. Every
request is read into memory, so it must fit into it. Bear in mind, that if you use
file-upload-fields a request might be larger than just a few bytes.
The value defaults to 0, which means, that there is no limit at all.
Example
<maxRequestSize>65536</maxRequestSize>
<maxRequestTime>seconds</maxRequestTime>
In daemon mode tntnet has a watchdog, which restarts tntnet when the maximum
request time is exceeded. This happens, when a request is in a endless loop or
otherwise hangs. Restarting tntnet looses all active sessions and the currently
running requests. Therefore the timeout should be well long enough for the longes
request.
The default value is 600 seconds, which is normally much longer than a http request
should run. If the Timeout is set to 0, the watchdog is deactivated.
Example
<maxRequestTime>1200</maxRequestTime>
<minThreads>number</minThreads>
Tntnet uses a dynamic pool of worker-threads, which wait for incoming requests.
MinThreads specifies, how many worker threads there have to be. This defaults to 5.
Example
<minThreads>10</minThreads>
<minCompressSize>number</minCompressSize>
Http-compression for replies smaller than this are not compressed at all.
The default value for this is 1024.
Example
<minCompressSize>256</minCompressSize>
<mimeDb>filename</mimeDb>
Specify filename for mime db. The default is /etc/mime.types.
The format of the file is just like this /etc/mime.types. A mime type is followed
after white space by a list of file extensions delimited by white space.
<maxThreads>number</maxThreads>
Tntnet uses a dynamic pool of worker-threads, which wait for incoming requests.
maxThreads limits the number of threads.
The default is 100.
Example
<maxThreads>200</maxThreads>
<pidfile>filename</pidfile>
When run in daemon-mode, tntnet writes the process-id of the monitor-process to
filename. When the monitor-process is deactivated, the pid of the worker-process is
written. This ensures, that sending a sigkill to the the stored process-id stops
tntnet.
Example
<pidfile>/var/run/tntnet.pid</pidfile>
<queueSize>number</queueSize>
Tntnet has a request-queue, where new requests wait for service. This sets a
maximum size of this queue, after wich new requests are not accepted.
The default value is 1000.
Example
<queueSize>50</queueSize>
<sessionTimeout>seconds</sessionTimeout>
This sets the number of seconds without requests after which a sesssion is timed
out.
The default value is 300 seconds.
Example
<sessionTimeout>600</sessionTimeout>
<socketReadTimeout>milliseconds</socketReadTimeout>
A worker-thread waits for some milliseconds on incoming data. If there is no data,
the job is put into a queue and another thread waits with poll(2) on incoming data
on multiple sockets. The workerthreads are freed and they can respond to other
requests quickly. The default value is 10 milliseconds, which is good for normal
operation. A value of 0 results in non-blocking read. If timeout is reached, this
does not mean, that the socket is closed. A small timeout reduces contextswitches
on slow connections.
Example
<socketReadTimeout>0</socketReadTimeout>
<socketWriteTimeout>milliseconds</socketWriteTimeout>
This defines the time, how long the workerthreads wait on write. If the timeout is
exceeded, the socket is closed and the browser might not get all data. The default
value is 10000 milliseconds.
Example
<socketWriteTimeout>20000</socketWriteTimeout>
<threadStartDelay>ms</threadStartDelay>
When additional worker threads are needed tntnet waits the number of milliseconds
before it starts additional threads to prevent high load when starting many threads
at once.
The default value is 10ms.
Example
<threadStartDelay>1000</threadStartDelay>
<user>username</user>
Changes the user under which tntnet answers requests.
The user is changes using the system call setuid(2), which is only allowed, when
tntnet starts as root user.
Example
<user>www-data</user>
URL MAPPING
Tntnet is a web server, which receives http requests from a http client and answers them.
A http request has a url and other attributes, which are used to decide, how the answer
should look like. This is done my mapping urls to components.
A component is something, which generates a http reply. They are normally generated with
the ecpp compiler ecppc(1). The ecppc compiler generated C++ classes with component
names. The classes are compiled and linked into a shared library. Both the component name
and the shared library name is needed to identify a component.
The component identifier is a string built from the component name, the @ character and
the shared library name. A example is myclass@myapplication. This tells tntnet: load
shared library myapplication and call the component with the name myclass in that library,
which creates the reply to the request.
To tell tntnet, which component to call, url mappings must be configured.
Configuration is done in the xml section <mappings>. Multiple mappings can be configured
there. A mapping has a condition and a target. Tntnet looks in the list of mappings for
the first mapping, where the condition is met and uses that to call the component. The
component may return either a reply - then the request is done or a special value
DECLINED, which tells tntnet to continue in the list and look for the next mapping, where
the condition is met.
The component, which returns DECLINED may already have generated part of the request. This
is preserved for the next mapping. A common use case is to write a special component,
which just checks the user name and password. If the user name and password is valid,
DECLINED is returned and tntnet calls the next mapping where the condition is met.
Also when the condition is met, but the component could not be loaded, tntnet continues
with the next mapping.
When the end of the list is reached and no mapping returned a http reply code, tntnet
replies with http not found (404) error.
So how these mapping are specified then?
The mapping contains 3 kind of nodes:
conditions
Multiple conditions can be specified. All conditions must be met when the mapping
is to be used.
The most important is <url>, which contains a extended regular expression (see
regex(7) for details). This expression is checked against the url of the request.
If the url tag is omitted, the mapping is used for every url.
The condition <vhost> specifies the virtual host, for which this mapping is valid.
When this is specified, the mapping is only valid for requests, where the virtual
host matches the setting. The value is also a extended regular expression. Note,
that a dot matches any character in regular expressions, which may be irritating
here. If you want to specify a mapping for the all hosts of the domain tntnet.org,
you have to set <vhost>tntnet\.org$</vhost>. Also the dollar sign at the end is
important, since it matches the end of the string. Otherwise the mapping would be
also valid for a virtual host like tntnet.org.foo.com, which may not be what you
meant.
The condition method specifies the http method for which the mapping should be
considered. Again a extended regular expression is used.
The condition ssl is a boolean value. The value should be 0 or 1. The setting
checks, whether this mapping should be used depending on ssl. If the value is 1,
the condition is met, when the request is sent via ssl. If the value is 0, the
condition is met, when the request is sent without ssl.
target The mapping node contains a node <target>, which contains the component name, which
is to be called when the conditions are met.
The target may contain back references to the regular expression in the <url>
condition. Parts of the regular expression may be in brackets. In the target $1 is
replaced with the first bracketed expression, $2 with the second and so on.
This node is mandatory.
parameters
When the condition is met, additional parameters may be passed to the called
component. There are 2 nodes for this.
The node <pathinfo> can be requested in the component using request.getPathInfo().
If the node is not set, the url is set as path info.
The node <args> contains additional parameters, which can be passed to the
component. The node can have any number of nodes with values. The tags are used as
a parameter name and the content as the value. The method request.getArg(name)
returns the value of the specified name. When the node is not set, the method
returns a empty string. Optionally a diffrent default value can be passed to the
method as an additional parameter like request.getArg(name,defaultValue).
For compatibility reasons with older tntnet request.getArg accepts a numeric
argument. Previously the arguments did not have names but were accessed by index.
To emulate this, request.getArg with a numeric argument translates the number into
the name "argnumber". So accessing request.getArg(2) returns the value of the
argument with the name arg2. Accessing a numeric argument equal or greater than the
number of arguments (the first is number 0) used to be not allowed. Now a empty
string is returned.
Example
<mappings>
<!-- map / to index@myapp -->
<mapping>
<target>index@myapp</target>
<url>^/$</url>
<pathinfo>index.html</pathinfo>
</mapping>
<!-- map /comp.* or /comp to comp@myapp -->
<mapping>
<target>action@myapp</target>
<url></url> <!-- any url -->
<method>POST</method> <!-- but only on method POST -->
<vhost>localhost</vhost> <!-- and host header must be localhost -->
<ssl>1</ssl> <!-- and ssl is enabled -->
</mapping>
<mapping>
<target>$1@myapp</target>
<url>^/([^.]+)(\.(.+))?</url>
<args>
<extension>$2</extension>
</args>
</mapping>
</mappings>
LISTENERS
The section <listeners> specifies the ip addresses and ports, where tntnet waits for
incoming requests. Multiple listeners may be defined, when tntnet should listen on
multiple ip addresses or ports.
Each listener is defined in a node <listener>. A listener must have a subnode <ip> and
<port>. The node <ip> may contain a ip address or hostname or may be left empty. If the
node is empty, any interface is used. The <port> must contain the numeric port number.
The ip address may be a IPv4 or IPv6 address.
Optionally a tag <certificate> may be added. This enables ssl on the interface and
specifies the ssl host certificate for the interface. Note that tntnet can be built
without ssl support. In that case the certificate is just ignored and unencrypted http is
used here.
Example
<listeners>
<listener>
<ip></ip>
<port>80</port>
</listener>
<listener>
<ip></ip>
<port>443</port>
<!-- a certificate enables ssl -->
<certificate>tntnet.pem</certificate>
</listener>
</listeners>
AUTHOR
This manual page was written by Tommi Mäkitalo ⟨tommi@tntnet.org⟩.
SEE ALSO
tntnet (1)