\input texinfo @c $Id: lyskomd.texi,v 1.10 1999/04/17 00:05:27 ceder Exp $ @c %**start of header @setfilename lyskomd.info @include version.texi @settitle lyskomd @value{VERSION} Reference Manual @setchapternewpage odd @c %**end of header @ifinfo This is the reference manual for the lyskomd LysKOM server version @value{VERSION}. Copyright @copyright{} 1999 Lysator ACS. Permission is granted to make and distribute verbatim copies of this specification provided the copyright notice and this permission notice are preserved on all copies. @end ifinfo @dircategory LysKOM @direntry * lyskomd: (lyskomd). lyskomd reference manual. @end direntry @titlepage @sp 10 @title lyskomd Reference Manual @sp 2 @subtitle Server version @value{VERSION} @sp 2 @author by the lyskomd developers @page @vskip 0pt plus 1filll Copyright @copyright{} 1995-1999 Lysator ACS Permission is granted to make and distribute verbatim copies of this document provided the copyright notice and this permission notice are preserved on all copies. Modified versions of this document may be redistributed with the added condition that all modifications not cleared with the LysKOM development group are clearly marked and that the entire modified work be redistributed under the same conditions as the original. Permission is granted to copy and distribute translations of this manual into another language under the same conditions as for modified versions. @end titlepage @ifinfo @node Top, Copying, (dir), (dir) @comment node-name, next, previous, up @top lyskomd lyskomd is a server for the LysKOM conferencing system. This info file documents version @value{VERSION} of lyskomd. @menu * Copying:: lyskomd is free software. * Overview:: Overview of LysKOM. * Installation:: How to install lyskomd. * Configuration:: How to configure lyskomd. * Running lyskomd:: How to run lyskomd. * Administration:: Administering a LysKOM server. * Bugs:: Known bugs. @end menu @end ifinfo @node Copying, Overview, Top, Top @comment node-name, next, previous, up @chapter Copying lyskomd is free software. It is distributed under the Gnu General Public License version 2. The file COPYING in the top level of the distribution contains the text of the license. @node Overview, Installation, Copying, Top @comment node-name, next, previous, up @chapter Overview LysKOM is a conferencing system@footnote{Or in modern terms, enabling technology for Computer-Supported Cooperative Work (CSCW).}. Similar systems were QZ-KOM and PortaCOM@footnote{Also known as ``PottaKOM'' and ``BortaKOM''.}. The LysKOM system is copyrighted by Lysator Academic Computing Society and distributed under conditions of the GNU Public License. LysKOM and its documentation is provided ``as is'' without warranty of any kind. This reference manual documents version @value{VERSION} of the lyskomd LysKOM server. The lyskomd server is the work of several people. The main contributors have been Per Cederqvist @email{ceder@@lysator.liu.se}, Inge Wallin @email{inge@@lysator.liu.se}, Thomas Bellman @email{bellman@@lysator.liu.se}, David Byers @email{byers@@lysator.liu.se} and Peter Eriksson @email{pen@@lysator.liu.se}. Commercial service for LysKOM is available from Signum Support @url{http://www.signum.se/}. @section History In 1990, Per Cederqvist @email{ceder@@lysator.liu.se} and Peter Eriksson @email{pen@@lysator.liu.se} and a few other persons started to write the server. It was operational in the summer of 1990, even though the members of Lysator discovered a thing called MUD. We started using RCS on 20 May 1991. The first release was made on 16 Sept 1991. Around that time we switched from RCS to CVS, and ceder started to write pcl-cvs (a GNU Emacs front-end to CVS) instead of LysKOM. After a while, he started writing Bugtrack, to be able to handle all bug reports he recieved about pcl-cvs. He hopes to be able to devote some more time to LysKOM in the future. @node Installation, Configuration, Overview, Top @comment node-name, next, previous, up @chapter Installation Instructions for compiling and installing lyskomd are in the file INSTALL, located in the top level of the lyskomd distribution. Installation should be straightforward on most platforms. @node Configuration, Running lyskomd, Installation, Top @comment node-name, next, previous, up @chapter Configuration There are two configuration files for lyskomd. One defines the server options and the other defines aux-item types @ref{(protocol-a)The Aux-Item List,The Aux-Item List}. @menu * Server Configuration File:: The server configuration file. * Aux-Item Definition File:: The aux-item definition file. @end menu @node Server Configuration File, Aux-Item Definition File, Configuration, Configuration @comment node-name, next, previous, up @section Server Configuration File The server reads its configuration from a configuration file. The default configuration file is @file{/usr/lyskom/etc/config}. The location of the configuration file can be changed at run-time by supplying an argument to lyskomd. The configuration file is line oriented. Each line consists of a parameter name followed by a colon, and the value of the parameter. Empty lines and lines whose first non-blank character is a @code{#} are ignored. @menu * Parameter Types:: Types of configuration parameters. * Parameters:: Valid configuration parameters. @end menu @node Parameter Types, Parameters, Server Configuration File, Server Configuration File @comment node-name, next, previous, up @subsection Parameter Types Every parameter has a type. The legal types are: @table @code @item bool The parameter can be true or false. Legal values are @code{on}, @code{true}, @code{yes} and @code{1} for true and @code{off}, @code{false}, @code{no} and @code{0} for false. @item locale-name The parameter is a locale name. The value must be a legal locale name of the system where lyskomd is running. @item path The parameter is a path name. The value must be a legal path on the system where lyskomd is running. Most paths you can specify can be either absolute paths (if they begin with a @samp{/}) or paths relative to the installation prefix which is specified at compile time or with the @samp{Prefix} parameter in the configuration file. @item portname The parameter is a TCP/IP port. It can be a symbolic port name (traditionally looked up in @file{/etc/services}) or a port number. @item int The parameter is a number of some sort. It can be a conference number, text number or perhaps a timeout. @end table @node Parameters, , Parameter Types, Server Configuration File @comment node-name, next, previous, up @subsection Parameters @table @code @item Locale: @var{string} Use @var{string} as the locale to run in. This parameter is only available om systems which support the @code{setlocale} call. If this parameter is not set, no call to @code{setlocale} will be made. The default is unset. @item Force ISO 8859-1: @var{bool} This option is provided for those with dysfunctional computers that cannot handle @code{setlocale} properly. If this is set, lyskomd will handle texts according to the ISO 8859-1 (latin1) alphabet. Default is off. @item Prefix: @var{path} All files that the server uses are found in sub-directories of this directory. The default value of this parameter is set at compile time. The default at compile time is @file{/usr/lyskom}. @item Send async: @var{bool} Do not send any non-requested messages. This disables the sending of messages about events in the server to all connections. Use of this parameter is not recommended. Default is on. @item Client port: @var{portname} Listen for new clients on port @var{portname}. The default is 4894, which is what all clients expect. Do not change this parameter without really good reason. @item Mux port: @var{portname} Listen for mux connections on @var{portname}. Muxes can be used to multiplex several clients on a single file descriptor. The mux runs as a separate process. This was used historically when LysKOM ran on a machine were only 20 file descriptors coule be open at once. The mux code has not been released. Send a mail to @email{bug-lyskom@@lysator.liu.se} if you need it. The default port number is 4895. @item Presentation of conferences: @var{int} The number of the conference where presentations should be sent. Defaults to 1. This option is ignored in lyskomd 1.9 and later. Set this using dbck or the @ref{(protocol-a)set-info,set-info}. @item Presentation of persons: @var{int} The number of the conference where presentations should be sent. Defaults to 2. This option is ignored in lyskomd 1.9 and later. Set this using dbck or the @ref{(protocol-a)set-info,set-info}. @item Motd-conference: @var{int} The number of the conference where "message-of-the-day" messages should be sent. Defaults to 3. This option is ignored in lyskomd 1.9 and later. Set this using dbck or the @ref{(protocol-a)set-info,set-info}. @item News-conference: @var{int} The number of the conference where news of interest to the readers of this LysKOM server should be written. This is typically a conference with very low traffic which everyone shoule be a member of. Clients should offer new users to join it. Defaults to 4. This option is ignored in lyskomd 1.9 and later. Set this using dbck or the @ref{(protocol-a)set-info,set-info}. @item Message of the day: @var{int} Default message-of-the-day of this server. The text will be shown automatically by conforming LysKOM clients when a user logs on. This option is ignored in lyskomd 1.9 and later. Set this using dbck or the @ref{(protocol-a)set-info,set-info}. @item Garb: @var{bool} Should the database be automatically purged of old texts? The default is on. @item Never save: @var{bool} Do not use unless you know what you are doing. (Note: there is currently no-one in the LysKOM development group which knows exactly what this option does, so if you @i{do} know what you're doing, by all means let us know!) The default is off. @item Log accesses: @var{path} This parameter can only be set if the server has been compiled with @code{LOGACCESSES} defined. It will save a trace of all activity in the database to a file, for later use in simulations et c. Compiling with @code{LOGACCESSES} slows the server down quite a lot, so it is normally not defined. @item Data file: @var{path} The path relative to the installation prefix where part of the database is kept. The default is @file{db/lyskomd-data}. @item Backup file: @var{path} The path relative to the installation prefix where a backup of the database is kept. This file will always contain a complete database, but it may be a little out-of-date. Default is @file{db/lyskomd-backup}. @item Backup file 2: @var{path} The path relative to the installation prefix where a previous generation of the backup of the database is kept. This file may be needed if an error in the backup file is detected during the creation of the data file. Default is @file{db/lyskomd-backup-prev}. @item Text file: @var{path} The path relative to the installation prefix where the actual texts in the database are kept. Default is @file{db/lyskomd-texts}. @item Text backup file: @var{path} When dbck is run with the @code{-g} option (@ref{(dbck)Invoking dbck,Invoking dbck}, it will store the previous contents of the text file in the file specified by this option. The path is relative to the installation prefix. This file is never used by lyskomd itself. Default is @file{db/lyskomd-texts-backup}. @item Log file: @var{path} The path relative to the installation prefix where log messages from lyskomd are written. Default is @file{etc/server-log}. @item Log statistics: @var{path} Whenever lyskomd receives a SIGUSR1 it will append a timestamp and a count of how many different atomic calls have been made in this file. The path is relative to the installation prefix. Default is @file{etc/lyskomd-log}. @item Pid file: @var{path} When lyskomd is up and running it will write its pid in this file. The path is relative to the installation prefix. This file is used so the @code{updateLysKOM} script can easily find out what pid the LysKOM server has. Default is @file{etc/pid}. @item Memory usage file: @var{path} When lyskomd exits normally it appends some info on its usage of memory to this file. The path is relative to the installation prefix. Almost any memory leak bugs should be detectable by looking in this file. Default is @file{etc/memory-usage}. @item Aux-item definition file: @var{path} This file defines which aux-items the server should support and how it should handle them. @xref{Aux-Item Definition File} for more details. The path is relative to the installation prefix. Default is @file{etc/aux-items.conf}. @item Status file: @var{path} This file is created by @code{komrunning} to indicate that lyskomd should currently not be running. When this file exists @code{updateLysKOM} will send it a @code{SIGHUP} signal, so that it saves the database and dies. Default is @file{etc/status}. @item Core directory: @var{path} The Directory where core dumps are written. This path is relative to the installation prefix. Default is @file{cores}. @item Idle timeout: @var{int} Number of milliseconds to sleep when there is nothing for lyskomd to do. Default is @code{120000} (two minutes.) @item Garb timeout: @var{garb} Number of milliseconds to sleep when the server is garbage-collecting texts, but has nothing else important to do. Default is @code{100} (0.1 seconds.) @item Sync timeout: @var{sync} Number of milliseconds to sleep when lyskomd is saving its database. Defaults to 0. @item Permissive sync: @var{bool} Turning this option on lets any session sync the LysKOM database. Turning it off restricts the operation to LysKOM administrators. Default is off. @item Garb interval: @var{int} Number of minutes between each garb sweep. Defaults to @code{1440}, that is, a garb sweep will be run once per day. @item Sync interval: @var{int} Number of minutes between syncs. The current version of lyskomd keeps changes to the database in memory until they are synced to disk. This parameter specifies the number of minutes the server waits before attempting to dump the database. The default is @code{5}. @item Sync retry interval: @var{int} If anything goes wrong while trying to dump the data base (such as if the disk is full), lyskomd will wait for this many minutes before trying again. Default is @code{1}. @item Max conference name length: @var{int} The maximum length of conference names. The default is @code{60}. @item Max password length: @var{int} Only the first eight characters of the password are currently significant, even if this number is much larger. The default is @code{128}. @item Max what am I doing length: @var{int} The maximum length of the string permitted in the protocol A call @ref{(protocol-a)change-what-i-am-doing, change-what-i-am-doing}. The default is 60. @item Max username length: @var{int} The maximum length permitted for user names. Default is 128. @item Max text length: @var{int} The maximum length allowed for a text. The default is 131072 characters. @item Max broadcast length: @var{int} The maximum length allowed for broadcast messges. The default is 1024 characters. @item Max regexp length: @var{int} The maximum length allowed for regexps in various calls. The default is 1024 characters. @item Max marks per person: @var{int} The maximum number of marks a person is allowed to have. The default is 2048. @item Max marks per text: @var{int} The maximum number of marks a text can have. The default is 1024. @item Max recipients per text: @var{int} The maximum number of recipients of a text. The default is 512. @item Max comments per text: @var{int} The maximum number of comments a text can have. The default is 128. @item Max footnotes per text: @var{int} The maximum number of footnotes a text can have. The default is 32. @item Max links per text: @var{int} FIXME: What is this? @item Max mark_as_read chunks: @var{int} FIXME: What is this? @item Max super_conf loop: @var{int} FIXME: What is this? @item Max accept_async len: @var{int} Maximum length of list accepted in the accept_async call. Default is 128. @item Max aux_items deleted per call: @var{int} Maximum number of aux_items that can be deleted in one call. Default is 128. @item Max aux_items added per call: @var{int} Maximum number of aux_items that can be added at once. Default is 2048. @item Default garb nice: @var{int} Each conference has a lifetime for texts written in it. The lifetime is counted in days, and can be set for each conference by the administrator of the conference. This is the default value assigned to new conferences. Default is 77 days. @item Default keep commented nice: @var{int} A text will not be removed if it has comments newer than a certain number of days. This number can be set for each conference. This parameter specifies the default value for that number of days. The default is 77. @item Max client transmit queue: @var{int} Max number of pending data blocks in the reply queue to a client. If there is ever more than this many data blocks in the queue the client will be disconnected. Each atomic question typically generates two data blocks. Default is 300. @item Max simultaneous client replies: @var{int} This is a performance tuning parameter of little real interest. Default is 10. @item Open files: @var{int} Try to persuade the operating system to allow lyskomd to have this many open file descriptors simultaneously. Each client that is connected to the server occupies one file descriptor, and lyskomd needs several file descriptors for internal purposes. Default is to not use this parameter. @item Anyone can create new persons: @var{bool} If this is set, anyone can create a new person, even if he lacks special bits for doing so. Default is on. @item Anyone can create new conferences: @var{bool} If this is set, anyone can create a new conferences, even if he lacks special bits for doing so. Default is on. @item Allow creation of persons before login: @var{bool} If this is set, persons can connect the the server and create a new person without logging in. This is how new users register in open environments. If this option is off, then new persons can only be created by existing users. The default is on. @item Default change name capability: @var{bool} If this is set, new users are created with the ability to change their own name. Default is on. @item Ident-authentication: @var{policy} Decide how strictly the server should use the IDENT protocol. The policy can take any of three values: @table @asis @item @code{off} or @code{never} Do not use the IDENT protocol. @item @code{on} or @code{try} Use it, but allow logins even if the lookup fails. @item @code{require} or @code{required} Disallow connections if the server cannot find a IDENT login name. @end table @item Log login: @var{bool} Should logins be logged to the log file? Default value is off. @item Cache conference limit: @var{int} How many conference statuses the server cache should hold in main memory. Default is 20. This parameter should be set to at least the number of expected simultaneous logins. @item Cache person limit: @var{int} How many person statuses the server cache should hold in main memory. Default is 20. This parameter should be set to at least the number of expected simultaneous logins. @item Cache text_stat limit: @var{int} How many text statuses the server cache should hold in main memory. The default is 20. This parameter should be increased on busy servers. @item Echo: @var{string} Write @var{string} in the log when the config file is read. @item Jubel: @var{pers_no} @var{text_no} States that @var{pers_no} is not allowed to create text number @var{text_no}. Default is unset. @item Jubel: @var{pers_no} @var{dividend} @var{remainder} States that @var{pers_no} is not allowed to create any text number @var{T} which meets the condition @var{T} % @var{dividend} == @var{remainder}. Default is unset. @item Add members by invitation: @var{bool} If this is set, then adding others as members to a conference sets the invitation bit of the membership. If this is off, the membership bit is set to whatever the caller specifies. The default is on. @item Allow secret memberships: @var{bool} If this is set, then memberships may be secret. Otherwise any attempt to create a secret membership or change an existing membership to a secret membership will fail. The default is on. @item Allow reinvitations: @var{bool} If this is set, then it is possible to set the invitation bit of a membership even after it has been cleared. If it is not set, then the invitation bit of a conference type can only be set when the membership is created. It can be cleared at any time. The default is off. @item Regexps use collate table: @var{bool} If this is set, regexp matching of conference names uses the same collate table used by regular matching. This usually implies that the regexp ``foo'' will match ``foo'', ``Foo'', ``fOo'' and several other variants. The defalt is on. @end table @node Aux-Item Definition File, , Server Configuration File, Configuration @comment node-name, next, previous, up @section Aux-Item Definition File The default aux-item definition file should not be changed unless it is really necessary. The need to change the definitions will probably only arise at installations used for client or server development. The location of the aux-item definition file is specified by the @code{Aux-item definition file} option in the server configuration file. The default location is @file{/usr/lyskom/etc/aux-items.conf}. @subsection Syntax of the Aux-Item Definition File The aux-item definition file contains a sequence of aux-item definitions. Each definition specifies one type of predefined aux-item: its number, name, and properties. Empty lines and all characters from a # character to the end of the line are ignored. Each entry has the following format: @example tag : name (target, target, ... ) @{ field = value; field = value; ... @} @end example @var{tag} is an integer, the aux-item's tag. If a tag is defined more than once, the last definition is used. The @var{target}s specify what kind of objects aux-items with tag @var{tag} can be added to. Valid targets are: @table @code @item any Aux-items with the specified tag can be added to any object in the database. This is shorthand for @code{text,conference,letterbox,server}. @item text Aux-items with the specified tag can be added to texts. @item conference Aux-items with the specified tag can be added to conferences that are @i{not} letterboxes. @item letterbox Aux-items with the specified tag can be added to conferences that are letterboxes. @item server Aux-items with the specified tag can be added to the server itself. @end table It is legal to add one of the keywords @code{create} or @code{modify} before any target except @code{server}. If @code{create} is specified, aux-items with the specified tag can only be added when an object is being created. They cannot be added later. If @code{modify} is specified, aux-items with the specified tag can only be added after an object has been created. They cannot be added when the object is being created. Each @var{field}/@var{value} pair specifies a property of aux-items with the specified tag. Most values are boolean or trillian. Legal values for either type are @code{true} and @code{false}. Boolean values have reasonable defaults; trillian values can be unset. @table @code @item author-only Boolean, default false. When true, only the author of a text or supervisor of a conference can create items with this tag. @item supervisor-only Boolean, default false. When true, only the supervisors of the author or letterbox can create items with this tag. In all likelihood, the implementation of this flag is screwed up. @item permanent Boolean, default false. When true, aux-items with this tag cannot be deleted once they have been created. (They will be deleted automatically when the object they are assigned to is deleted.) @item unique Boolean, default false. When true, there can only be one non-deleted item with this tag per creator. @item inherit-limit Integer, default 0. The maximum number of times items with this tag can be inherited, plus one. Zero means an unlimited number of times, one means no times, 2 means once and so forth. This number overrides the inherit-limit set by the client only if that number is higher than this one. @item inherit Trillian. When set, the inherit bit on new items with this tag is forced to the specified value. @item secret Trillian. When set, the secret bit on new items with this tag is forced to the specified value. @item hide-creator Trillian. When set, the hide-creator bit on new items with this tag is forced to the specified value. @item dont-garb Trillian. When set, the dont-garb bit on new items will be forced to the specified value. @item reserved-2 @item reserved-3 @item reserved-4 Trillian. When set, these flags force the values of the three reserved bits in the aux-item flags field. These should only be used by lyskomd developers, and then only very carefully. @item validate String, default none. When set, this specifies a regexp that must match the data field in newly created items with this tag. If the regexp fails to match, then the item will not be created. The syntax for strings is essentially the same as the syntax used in C files. @end table There are a few fields which specify actions the server is to take when something happens to aux-items with the specified tag. Each of these values is a function specification, the name of a trigger function defined in lyskomd. The syntax for functions is the name followed by an empty pair of parens. It is not possible to pass arguments to the functions yet. @table @code @item add-trigger Function to call when an item with the specified tag is added to an object. @item delete-trigger Function to call when an item with the specified tag is scheduled for deletion. @item undelete-trigger Function to call when an item with the specified tag scheduled for deletion is unscheduled. It should undo the effects of the delete trigger. @end table @node Running lyskomd, Administration, Configuration, Top @comment node-name, next, previous, up @chapter Running lyskomd This section explains how to run lyskomd, the files it uses and how it can be controlled while running. @menu * Invoking lyskomd:: How to run lyskomd. * Signals:: How to control lyskomd with Unix signals. * Files:: Files used by lyskomd. @end menu @node Invoking lyskomd, Signals, Running lyskomd, Running lyskomd @comment node-name, next, previous, up @section Invoking lyskomd @example lyskomd [-d] [@var{config-file}] @end example The option @code{-d} adds one to the debug level. The amount of output on stderr is increased for each time the option is specified on the command line. Furthermore, if this option is used, lyskomd will not run as a daemon, but will stay in forground mode. Using one @code{-d} makes the process print a `>' for every timeout, a message for every person that is connecting or disconnecting and a message for every successful or unsuccessful communication to the process. The optional @var{config-file} argument can be used to specify the server configuration file. @xref{Server Configuration File}. @node Signals, Files, Invoking lyskomd, Running lyskomd @comment node-name, next, previous, up @section Signals It is possible to control some aspects of lyskomd using Unix signals. The following signals have special meaning to the server: @table @code @item SIGHUP Logs out all sessions, saves the database and exits normally. @item SIGQUIT Saves the database and dump core. (This should only be used for debugging purposes.) @item SIGUSR1 Print statistics about how often different commands have been used since the process started. @item SIGUSR2 Forks a child that immediately dumps core. The main process just waits until the child is done and then continues. @end table @node Files, , Signals, Running lyskomd @comment node-name, next, previous, up @section Files Used by lyskomd All file names can be changed in the server configuration file. @xref{Parameters}. @table @file @item /usr/lyskom Default value of the @code{Prefix} parameter. The default of this value is set at compile time, but it can be changed in the server configuration file. @xref{Parameters}. @item @code{Prefix}/db/lyskomd-data Half of the database: all status information. @item @code{Prefix}/db/lyskomd-texts The other half of the database: the actual texts. @item @code{Prefix}/db/lyskomd-backup A backup copy of @file{lyskomd-data}. Never, ever delete this file unless you know what you are doing, or you may lose the entire data base. Most of the time this is the only complete database file! @item @code{Prefix}/etc/pid File with the pid of the lyskom-process. @item @code{Prefix}/etc/memory-usage On normal exit, @code{lyskomd} will append some statistics to this file. It can be used for detecting memory leaks. @item @code{Prefix}/etc/aux-items.conf This file contains definitions of the aux-items that the server should support. It is read by @code{lyskomd} at startup. @end table @node Administration, Bugs, Running lyskomd, Top @comment node-name, next, previous, up @chapter Administration The first thing you will have to do is to follow the instructions in the file @file{INSTALL}. This will set up the LysKOM system with a database containing a few necessary conferences and one person - the administrator. Once the LysKOM system is running, there is not much you will have to do to keep it that way. One thing to remember is that the current release of the server has an incomplete handling of garbage collection of the database. The database is split into two files, the information file and the text file. Newly written texts are concatenated to the text file and old texts are never removed. The information file contains information about conferences, users and where in the text file the texts are. This file is properly garbage collected, but not the text file. There is a program called @code{dbck} (Data Base Check) which is used to check the consistency of the LysKOM database. This program can also be used to shrink the text file. To do this, just type @samp{dbck -g}. @xref{(dbck)}. When @code{dbck} is to be run on the database, the LysKOM server @emph{must} be stopped, or unrepairable damage may result. See below for a description on how to stop the server. There is a program called @code{updateLysKOM} which is used to ensure continuous operation. This program should be run with certain intervals, for instance from @code{cron}. If the LysKOM server has died for some reason, @code{updateLysKOM} restarts it. If the server is still running properly, @code{updateLysKOM} sends a signal (@code{SIGUSR1}) to it, which causes the server to write some statistics to a file named @file{etc/lyskomd-log} in the lyskom directory. Taking the server down cleanly can be done in two ways: through the use of the LysKOM protocol on a socket, preferably through the use of a suitable client, or by sending the signal @code{SIGHUP} to it. This will cause the server to save the database and close all client connections. It will also create a file named @file{etc/memory-usage} in which the memory usage of the server is reported. To prevent @code{updateLysKOM} from restarting a server, create a file named @file{/usr/lyskom/etc/status}. The file should contain a valid mail address on the first line. @code{updateLysKOM} will not restart the server as long as that file exists. In addition, if the file is between 1 and 2 hours old an email will be sent to the mail address found in the file. If the file is older than that, an error message will be printed on stderr and updateLysKOM will exit with a non-zero exit status. cron is expected to deliver the error message to an operator. The shell script @code{komrunning} can be used to start and stop the LysKOM server. With no arguments, it will report the status. @example komrunning off @end example will (attempt to) shut down the server, creating the file @file{/usr/lyskom/etc/status}. If the user running @code{komrunning} doesn't have permission to send signals to @code{lyskomd} the actual shutdown will be delayed until the next time that @code{updateLysKOM} is run. @example komrunning on @end example will restart the server. The actual starting of the server will be done by @code{updateLysKOM} the next time it is run. @code{komrunning} only removes the lock file. @node Bugs, , Administration, Top @comment node-name, next, previous, up @chapter Known Bugs @itemize @bullet @item lyskomd should re-read the config file when a @code{SIGHUP} is received. @item lyskomd should terminate when a @code{SIGINT} or @code{SIGTERM} is received. @item The security policy is vague and the implementation is frayed at the edges. @item The choice of asynchronous messages is not very good. @item The server uses too much memory. @end itemize @contents @bye