- Mirroring
-
-Sometimes it can be useful to have the same ELOG logbook on two different computers. This
-might be the case if you travel with your laptop, but want to keep the logbooks from your
-desktop computer on the laptop. The problem is that if you add an entry on your laptop,
-the logbooks on the laptop and the desktop get out of sync. Merging only the ELOG database
-files does not help, since two entries could be made at the same day on the laptop and
-the desktop, which would lead to a conflict in that day's database file.
-
-
-To solve this problem, mirroring was introduced from Version 2.5.0 on. This technology
-allows to synchronize one ELOG server with a number of other servers on a per-entry basis. No
-additional software is needed, only two elogd daemons talking to each other. The synchronization
-can be executed manually or periodically. If entries are changed/added/deleted on both sides,
-they get merged properly during synchronization. In order to minimize network traffic, each
-ELOG server calculates a MD5 checksum for each message, which gets exchanged during synchronization.
-Only when the MD5 checksum differs, entries are transferred.
-
-
-To set-up mirroring, install two elogd servers on two machines (for testing purpose that also
-works on one machine with two elogd servers running on different ports). This can be done in
-two ways:
-
-
-- Automatic configuration
-
-A complete elog server can be transferred to a secondary server using the clone
-command. Assume the existing server resides at http://master.your.domain/,
-and you want to mirror this server to a new location at http://slave.your.domain/.
-You do that by installing the elog package at the slave machine, and then executing on the slave:
-
-
elogd -C http://master.your.domain
-
-This command tells elogd to retrieve the configuration file, and optionally all logbook entries
-and password files from the master machine. Note that both servers must be version 2.5.4 or later.
-In case of trouble, you can turn on verbose messaging:
-
-
elogd -v -C http://master.your.domain
-
-which could give some hints. If a logbook on the master server uses restricted access, you have
-to specify the admin user name and password. After everything has been transferred, you can start
-elogd in the normal way.
-
-
- Manual configuration
-
-First, copy the elogd.cfg file from the master to the slave server. Make sure that
-the files are identical (except the port setting if you run two servers on the same
-machine). Then, add the following configuration options. They should be put
-into the [global] section of the cofiguration file:
-
-
-Mirror server = <URL-list>
-
-This statement specifies one or more mirror servers. Each URL must contain the host, port and
-possible subdirectory of the remote server, as if you would access it through your browser.
-A typical statement looks like:
-
-Mirror server = myhost.mydomain.org:8080, http://another.server.org/elog/
-
-
-The URL should not contain any logbook name, this gets added automatically. The second
-example contains a subdirectory, which is typically used if the elogd daemon runs
-under an Apache proxy.
-
-
Mirror config = 0 | 1
-
-Normally, only the logbook entries are mirrored. One can also mirror the contents
-of the elogd.cfg configuration file for individual logbooks. This can be turned on
-by setting this option to 1. Default is 0.
-Only the individual logbook section is mirrored, not the [global] section. Settings
-which are specific to one server, for example the URL = statement,
-should then be kept in the [global] section, so that they are not mirrored between
-different servers.
-
-Mirror cron = Minute Hour Day Month Weekday
-
-This statement turns on periodic mirroring. The format is similar to the UNIX
-cron command. Each of the five values can either be an
-asterisk, which means all possible values, a comma-separated list or a range.
-It can be explained most easily with examples:
-
-
-| Mirror cron= | meaning |
|---|
-
-| 0 3 * * * | Every night at 3:00 |
-
| 30 7 1,15 * * | At 7:30 every 1st and 15th of a month |
-
| 0 12 10 10 * | Once a year at 12:00 on my birthday |
-
| 0 7-18 * * 1-5 | Once every hour from 7:00 to 18:00 from Monday to Friday |
-
-
-Valid ranges for each value are:
-
-
-| Minute | 0-59 |
-
| Hour | 0-23 |
-
| Day | 1-31 |
-
| Month | 1-12 |
-
| Weekday | 0-6 with 0=Sunday, 1=Monday, etc. |
-
-
-If mirroring is turned on, it is advisable to use the Logfile =
-option to turn on logging, so that one can inspect the logfile to see if the mirroring
-works correctly.
-
-Mirror user = <name>
-
-If periodic mirroring is used via the Mirror cron = statement
-and the remote logbook uses user-level access, this statement specifies the
-user name which is used to log in to the remote logbook. The password is taken from
-the local password file and has to match the password in the remote password file,
-otherwise the access is not allowed. The user name is typical the login name of
-the administrator.
-
-Mirror simulate = 0 | 1
-
-If one wants to try out mirroring without causing any harm, one can turn on this flag.
-During synchronization, entries are compared and necessary transfers are displayed,
-but not executed. Default is 0.
-
-Mirror exclude = 0 | 1
-
-By default, all logbooks are mirrored. Individual logbooks might be excluded from
-mirroring by putting Mirror exclude = 1 in their individual logbook
-section of the configuration file (Not the [global] section).
-Default is 0.
-
-
-
-
-If the statement Mirror server is present in the configuration file, a new
-menu option "Synchronize" appears on the elog page. Clicking on
-this menu options starts the synchronization:
-
-
-
-On the left side one sees the entry ID's. Entries which are equal locally and remotely
-are not displayed. Here are the rules for synchronization:
-
-
-- If an entry has been modified locally but not remotely, it is submitted to the remote
-server.
-
-
- If an entry has been modified remotely but not locally, it is retrieved from the
-remote server and saved locally.
-
-
- If an entry has been modified remotely and locally since the last synchronization,
-an error is shown that the entries are conflicting. In that case one has to merge
-the entries manually and delete it on one side.
-
-
- If an entry has been deleted locally, it is deleted remotely.
-
-
- If an entry has been deleted remotely, it is deleted locally.
-
-
- If a new entry exists locally, it is submitted.
-
-
- If a new entry exists remotely, it is retrieved from the remote server and
-saved locally.
-
-
- If new entries exist locally and remotely having the same entry ID, the local
-entries are changed to have higher entry IDs, then the remote ones are retrieved. Care
-should be taken if external links (such as
elog:123) to the
-local entries are used, since they will point afterwards to the wrong entry.
-
-
-
-By starting the synchronization on one elogd server, this server becomes the client
-and the other one becomes the server. This means that the local server actively compares
-the local and the remote messages, and updates one or the other if necessary.
-The other (remote) server does not need to have any mirror option in its configuration
-file, since the local server simulates a web browser to send and retrieve messages to
-the remote server. It is however allowed that the remote server also contains some
-mirror settings in the configuration file, this way the synchronization can be
-started from both servers.
-
-
-
-
-
-
+...
+
+
+
+
+ The passwords are encoded. New users can either be created by hitting
+ Register as new user on the login page if Self register =
+ 1 in the configuration file, or by the admin user in the
+ Config page by pressing New user. When a user is logged it,
+ the entry for this user can be modified via the Config command.
+
+
+ To start a new password file, follow these steps:
+
+
+ - Specify a password file name with
Password file =
+ <file> in the configuration file
+
+ - Set
Self register = 1 in the configuration file
+
+ - Connect to the logbook. You will be presented the login page. If you
+ have a
Guest menu commands entry, you have to click
+ on "Login" to get that screen.
+
+ - Click on "Register as new user"
+
+ - Enter your login information and save it
+
+ - Add
Admin user = <user> into the
+ configuration file, using your login name from above
+
+ - If you now enter the "Config" page, you can add other users
+
+ - Remove the self registration option if you like
+
+
+
+ The presence of a password file requires all users to "log in"
+ using their name and password, except when a guest login is allowed via
+ the "Guest menu commands" option. An additional advantage of this
+ method is that the user name can be used as an attribute value for
+ creating logbook entries. For example, the following line could be added
+ to the configuration file to fill in the Author and the
+ Email attributes with the current user name and email:
+
+
+ -
+
Attributes = Author, Email, ...
+
+
+
+ -
+
Subst Author = $long_name from $remote_host
+ Subst Email = $user_email
+
+
+
+ Thus the author name is not user-input anymore, ensuring the entry always
+ contains the actual user name. For a full listing of substitutions, see
+ the "Subst <attrib>" option.
+
+
+ The user name and password are stored as cookies on the user side. The
+ expiration is controlled by the Remember me checkbox
+ during the login. If unchecked, the cookies expire after the current
+ browser session. If checked, they expire after 31 days by default, which
+ can be changed with the Login expiration option,
+ giving the expiration time in hours. Setting this to 24 for example,
+ makes the password expire after one day. If presistent cookies are not
+ desired, the Login expiration option can be set to
+ zero, in which case the Remember me checkbox is not
+ displayed.
+
+
+ The Admin user = <user list> is a list of one
+ or more user names, which have admin rights. They see a button
+ Change elogd.cfg on the config page by which they can
+ edit elogd.cfg through the web. They can also modify other users on the
+ Config page, change their passwords or remove them.
+ In addition, the admin user(s) can delete or edit entries from other
+ users if Restrict edit = 1.
+
+
+ The Login user = <user list> is a list of users
+ who can log in to a specific logbook. This option can be used with a
+ global password file. If a Password file is present
+ under the [global] section, the registered users in
+ that password file can log in to all logbooks. It might be required that
+ only certain users can log in to certain logbooks. This can be achieved
+ with the Login user option, places in each individual
+ logbook section in the configuration file. Only those users listed in
+ this statement can log in to the logbook where the statement is defined.
+ This method has the advantage over the option of definining individual
+ password files for individual logbooks that only one central password
+ file exists. So if a user changes her/his password, this becomes then
+ valid for all logbooks. If there would be individual logbook password
+ files, one would have to change the password in all logbooks
+ individually.
+
+
+ -
+
Self register = 0|1|2|3
+
+
+
+ With this option it is possible for new users to self-register an user
+ account. At the login page, a link is displayed "Register as a new
+ user" which leads the user to a configuration page where one can
+ enter the account name, full name and email address. A flag allows for
+ automatic email notification on new entries on the logbook. These
+ settings can later be changed with the Config menu command.
+
+
+ Setting this option to 0 disables self registration. With option
+ 1, users can silently register, while setting it to 2
+ causes elogd to send an email notification to the admin user(s). The
+ option 3 is used to only send an email notification to tha
+ admin users(s), which then can validate the account and commit it by
+ hitting the URL given in the email notification.
+
+
+ -
+
Allow password change = 0|1
+
+
+
+ Enables or disabled the ability for users to change their password. If
+ disabled, the "Forgot password? link in the login page is ommitted
+ as well. The admin user(s) can always change passwords.
+
+
+ -
+
Allow <command> = <user list>
+
+
+
+ Commands can be restricted to certain login names (separated by commas).
+ For each command in the list defined with the "Menu commands"
+ option, a list of user names can be specified, which are allowed to
+ execute that command. If the allow option is not present, all users may
+ execute that command by default.
+
+
+ -
+
Deny <command> = <user list>
+
+
+
+ Used to deny a certain command to a list of users. This can be used to
+ deny a guest user to enter new messages or modify a message.
+
+
+ -
+
Hosts allow = <list>
+
+ -
+
Hosts deny = <list>
+
+
+
+ These two settings can be used to restrict the access to the logbook to
+ certain computers. It is similar to the UNIX hosts.allow and
+ hosts.deny files. The list can consist of individual host names or
+ IP numbers, subnet masks like 123.213. (note the
+ trailing '.') or .mit.edu, or the word
+ All. The following rules are applied:
+
+
+ - Access will be granted when a host matches a pattern in "hosts
+ allow".
+
+ - Otherwise, access will be denied when a host matches a pattern in
+ "hosts deny".
+
+ - Otherwise, access will be granted.
+
+
+
+ These rules are applied before any password is checked. To debug
+ problems, start elogd with the "-v" flag, in which
+ case the rule checking is printed on the screen.
+
+
+ The global option Logfile = <filename> can be
+ specified to log all user login/logout activities plus all successful
+ user connections.
+
+
+ If any of the password statements are in the [global]
+ area of the configuration files, they are used for all logbooks. If one
+ logs in at one logbook, access is automaticlly granted to all logbooks.
+ If the password statements are in the individual logbook sections, one
+ has to log in to each logbook separately.
+
+
+
+
+
+
+ EMail notification
+
+
+ -
+
Email <attribute> <value> =
+ <list>
+
+ -
+
Use Email Subject = <string>
+
+ -
+
Use Email From = <string>
+
+ -
+
Use Email Heading = <string>
+
+ -
+
Use Email Heading Edit = <string>
+
+ -
+
Omit Email To = 0|1
+
+ -
+
Suppress Email to users = 0|1
+
+ -
+
Email attributes = <list>
+
+
+
+ To send email automatically when new entries are created in a logbook, a
+ SMTP host = entry must be present in the
+ [global] section of the configuration file. To submit
+ an email based on an attribute value, use the statement Email
+ <attribute> <value> = <list>. Whenever an
+ entry is submitted where attribute is equal to
+ value, an email notification is sent to the email
+ addresses in list. Several mail addresses may be
+ supplied, separated by commas. The mail addresses can contain attributes
+ via the "$" substitution. If a logbook contains for example an
+ attribute name which contains email names, then one can put
+ $name@domain to form a valid email address.
+
+
+ Multiple Email xxx statements may occur in a
+ configuration file. If either the attribute or the value contains one or
+ more blanks the string must be enclosed with quotation marks, as in:
+
+
+ -
+
Email type "Normal routine" = ...
+
+
+
+ The statement Email All = <list> sends an email
+ notification independent of the type and category. The Use Email
+ Subject = <string> statement specifies which text is
+ used as the email subject. The text can contain
+ $<attribute> statements which are substituted
+ with the current value of that attribute. For a full list of possible
+ substitutions, see the "Subst <attribute>" option. The
+ Use Email Heading = <string> specifies the text
+ for the email heading line. Default is "A new entry has been submitted
+ on [host]". The option Use Email Heading Edit =
+ <string> works the same way for updated (edited)
+ entries.
+
+
+ The option Use Email From = <string> is used
+ for the "From:" field in the email. Since more and more email
+ servers do not accept invalid "From:" addresses in order to reduce
+ spam mail, it might be important that a "real" email address is used in
+ the "From:" field. By default, the email address of the currently
+ logged in user is used for the "From:" field. If no user is logged
+ in, or the current user has not specified a email address in the password
+ database, the setting of the option Use Email From is
+ used for the "From:" field. Only if this option is not specified,
+ a generic address ELOG@<hostname> is used, which might be
+ rejected by the SMTP server however.
+
+
+ If the flag Omit Email To is set to 1, the
+ To: field in the email is left empty instead set to the real email
+ address of the recipients. This can be useful if one recipient should not
+ see the email addresses of the other recipients.
+
+
+ The flag Suppress Email to users can be set to
+ "1" if email should only be sent to the recipients of the
+ Email <attribute> <value> = <list>
+ statements but not to the users who have registerd for automatic email
+ notification.
+
+
+ If one wants to send only some attributes but not all in an email
+ notification, one can use the option Email attributes =
+ <list>, where a subset of the attributes can be
+ specified as well as their order.
+
+
+
+ Flags
+
+
+ -
+
Show text = 0|1
+ This flag controls if logbook entries contain a body text. If an
+ installation only requires attributes, this flag can be set to
+ 0. Default is 1.
+
+ -
+
Enable attachments = 0|1
+ This flag controls the attachment submission at the bottom of a message
+ entry page. If this flag is 0, the attachment section is not
+ displayed. This might be useful for logbooks where attachments are not
+ used. Default is 1.
+
+ -
+
Show attachments = 0|1
+ This flag controls the display of attachments such as images on normal
+ logbook pages. For logbooks with large images, this flag can be turned
+ off, so that attachments are only displayed when they are clicked on.
+ Default is 1.
+
+ -
+
Summary lines = x
+ This specifies the number of text lines displayed in a summary page.
+ Zero displays no text at all. The default is 3.
+
+ -
+
Reverse sort = 0|1
+ If this flag is 1, all listing pages (the default page view, the
+ result of a search query and the result of the "Last day" query)
+ is sorted in reverse order (newest entry down to oldest). The checkbox
+ Sort in reverse order on the search form gets checked by
+ default, too. Sorting in reverse order can make sense if there are many
+ pages of entries, but the ones entered last should be displayed on the
+ first page. Default is 0.
+
+ -
+
Search all logbooks = 0|1
+ If this flag is 1, the search form displays the button
+ "Search all logbooks". The default is 1. It might be
+ necessary to turn this option off for public logbooks if there are also
+ protected logbooks. Otherwise the search result would also display
+ entries from the protected logbooks.
+
+ -
+
Enable browsing = 0|1
+ If this flag is 1, browsing (hitting the next/previous button)
+ is enabled. For some rare occasions it might be necessary to disable
+ browsing. Default is 1.
+
+ -
+
Filtered browsing = 0|1
+ If this flag is 1, browsing (hitting the next/previous button)
+ can be filtered by individual attributes. If the checkbox next to an
+ attribute is checked, only messages with the same attribute value are
+ displayed. Default is 0.
+
+ -
+
Default encoding = 0|1|2
+ This specifies the default encoding for new entries. For installations
+ where entries are normally submitted as plain text, the default can be
+ set to 1. Set to 0 for ELCode encoding, to
+ 2 for HTML encoding. The default is 0.
+
+ -
+
Suppress default = 0|1|2|3
+ This specifies the default state of the "Suppress Email
+ notification" button on the new message entry form. For
+ installations where normally an email notification is not necessary,
+ the default can be set to 1. If an important entry is entered,
+ users can then uncheck the suppress box. If this value is set to
+ 2 , the suppress box is not displayed at all, so that an email
+ notification is always produced. If this value is set to 3, the
+ email notification is always suppressed. The default is 0.
+
+ -
+
Resubmit default = 0|1|2
+ This specifies the default state of the "Resubmit as new entry"
+ button on the edit message entry from. If this button is checked, the
+ current message is removed from its current position in the database
+ and submitted as a new message. This can for example be useful for
+ applications where users want to see which records have been updated
+ recently. If this value is set to 2, the resubmit box is not
+ displayed at all. The default is 0.
+
+ -
+
Resubmit replies = 0|1
+ If this flag is set to 1 and an entry is resubmited as a new
+ entry and this entry has replies, all replies of this entry are
+ resubmittes as new entries as well. The default is 0.
+
+ -
+
Display Email recipients = 0|1
+ If this flag is 1, the email recipients are displayed when a
+ logbook entry is entered which produces an email notification. Setting
+ this flag to 0 suppresses this display, in case users need not see that
+ email is being sent and to whom. The default is 1.
+
+ -
+
Email Format = <n>
+ Specifies what is sent in an email notification. <n> is the sum
+ of following flags:
+
+ - 1 : Send heading line "A new entry has been submitted..."
+
+ - 2 : Send attributes
+
+ - 4 : Send URL of logbook entry
+
+ - 8 : Send message body
+
+ - 16: Send optional attachments as email attachments
+
+ - 32: Send logbook name
+
+ - 64: Send names of optional attachments
+
+
So to send for example only the attributes and the URL, set
+ <n> to 6. Default is 63 (send everything).
+
+ -
+
Suppress Email on edit = 0|1
+ If this flag is 1, no email notifications are sent for edited
+ messages, only for new messages. The default is 0.
+
+ -
+
Email Encoding = <n>
+ Specifies in which encoding an email is sent. <n> is the sum of
+ following flags:
+
+ - 1 : Plain text
+
+ - 2 : HTML in the form of the plain text, but with ELCode
+ interpreted
+
+ - 4 : Full HTML page as shown in elog
+
+
So to send email in plain text and full HTML, set <n> to
+ 5. Some email clients have the possibility then to switch from
+ one view to the other. Default is 2.
+
+ -
+
Back to main = 0|1
+ If this flag is 1, the "List" button takes you back to
+ the logbook selection page instead to the last entry of the current
+ logbook. The default is 0.
+
+ -
+
Logout to main = 0|1
+ If this flag is 1, the "Logout" operation takes you back
+ to the logbook selection page instead to the login page. The default is
+ 0.
+
+ -
+
Restrict edit = 0|1
+ If this flag is 1, users can only edit their own messages. The
+ system checks automatically if the currently logged in user matches the
+ user supplied in an author attribute via the "Preset xxxx"
+ option. The default is 0.
+
+ -
+
Expand default = 0|1|2|3
+ This setting determines how messages are displayed in threaded mode.
+ Following options are possible:
+
+ -
+ 0: Only message heads are displayed, no replies. A "+"
+ indicates which message has one or more replies.
+
+ -
+ 1: Messages and replies are displayed, but no message body.
+
+ -
+ 2: Messages and replies are displayed together with the
+ first few lines of the message body. The number of lines is
+ controlled by the
Summary lines option.
+
+ -
+ 3: Messages and replies are displayed together with the full
+ message body.
+
+
The default is 1.
+
+ -
+
Hidden = 0|1
+ If this flag is 1, the logbook is not displayed in the initial
+ logbook selection page and in the logbook tabs. This can be useful for
+ logbooks which are only accessed for backup or archiving and would
+ clutter up the logbook list for the normal user. To access hidden
+ logbooks, one has to enter the logbook URL directly, or from a bookmark
+ list. Default is 0.
+
+ -
+
Use Lock = 0|1
+ If this flag is 1, a logbook entry is locked when someone
+ edits it (clicking the Edit command). A locked message gets
+ displayed with a little red sign indicating that the message is
+ currently edited by someone and should not be touched. This can be
+ helpful in installations where several people can edit messages.
+ Without locking, the second submission of an edited message overwrites
+ the first submission without notice. Although the sign gets displayed,
+ the message can still be edited (the lock can be "stolen"), but it's
+ the user's response to avoid any conflict.
+
+ Since elog cannot determine if someone keeps a message very long for
+ editing or if only the browser got closed, the locking can show up even
+ if the message is not kept for editing any more. In that case, the
+ message has to be edited again and submitted, to remove the origial
+ lock.
+
+ Note that logbooks accessible from the internet usually get scanned by
+ search engines. This can lead to situations where the Edit link
+ of each message is "followed" by a bot, resulting in all messages being
+ locked. In those cases locking has to be turned off.
+
+ Since release 2.5.4, some Javascript code has been added to avoid
+ unwanted locks. If someone edits an entry, but then goes away from that
+ page or closes the browser without submitting the changes, a pop-up
+ window appears asking the user to submit the changed entry. Although
+ this works for most browsers in most cases, it could be that Javascript
+ has been turned off in a browser, in which case the stale locks still
+ might appear.
+
+ Default for "Use Lock" is 0.
+
+ -
+
Show top groups = 0|1
+ When using top groups, the root of the elogd server is not accessible
+ any more, to avoid cases where one group can "see" the logbooks of the
+ other groups. If this feature is unwanted, the flag Show top
+ groups can be set to 1, in which case a
+ list of available top groups is shown.
+
+ -
+
Fix text = 0|1
+ With this options the main text body can be fixed, so that it cannot be
+ changed via the Edit button later. This feature can
+ be useful for set-ups where some attributed must be changed later, but
+ the text body should be preserved. The default is 0.
+
+ -
+
Case sensitive search = 0|1
+ This switch has two meanings. First, it defines the default state of
+ the Case sensitive check box in the "Find" page.
+ Second, it determines if the quick filters are case sensitive or not.
+ The default is 0.
+
+ -
+
Mode commands = 0|1
+ If this flag is missing or set to 1, the links "Full", "Summary"
+ and "Threaded" are shown on the top of the listing page. If this flag
+ is set to 0, these commands are hidden. This might be useful in
+ logbooks where only one mode makes sense for example.
+
+ -
+
Suppress execute default = 0|1
+ External scripts can be called with the Execute
+ new/edit/delete options. If these options are enabled, a
+ checkbox appears which lets the user suppress execution of the external
+ script. The setting of this flag determines the default state of this
+ checkbox. In logbooks where a script should only be ocasionally
+ executed, it could make sense to set this flag to 1.
+
+
+
+
+
+
+
+ Themes
+
+
+ Themes are layout and color schemes which determine the look and feel of
+ a logbook (sometimes called "skins"). A theme consists of a set of
+ images, which are used for the title banner and browse buttons, and a
+ Cascading Style Scheet (CSS), which defines the colors, fonts and spacing
+ of the ELOG pages.
+
+
+ Each theme resides in a separate subdirectory and is specified with the
+ theme = <dir> option in the configuration file.
+ Each theme can contain several CSSs, which can be selected with the
+ CSS = <filename> option.
+
+
+ A default theme is contained in the distribution. If new themes are
+ developed by users, they can be sent back to the author, to be included
+ in future releases.
+
+
+ To change colors and fonts, the source of a ELOG page can be examined.
+ All elements use CSS classes which are specified in the
+ class="<name>" statements. These classes can be
+ found in the .../themes/default/default.css file and
+ changed accordingly. For a description of all options, please consult for
+ example the W3C consortium.
+
+
+ If the CSS file is edited, most browsers require a "reload" to refresh
+ the modified file. The elogd daemon does not have to be restarted
+ after a change in the CSS file.
+
+
+ These two images display the same logbook entry using different themes:
+
+
+ 
+
+
+
+
+
+
+ Mirroring
+
+
+ Sometimes it can be useful to have the same ELOG logbook on two different
+ computers. This might be the case if you travel with your laptop, but
+ want to keep the logbooks from your desktop computer on the laptop. The
+ problem is that if you add an entry on your laptop, the logbooks on the
+ laptop and the desktop get out of sync. Merging only the ELOG database
+ files does not help, since two entries could be made at the same day on
+ the laptop and the desktop, which would lead to a conflict in that day's
+ database file.
+
+
+ To solve this problem, mirroring was introduced from Version 2.5.0
+ on. This technology allows to synchronize one ELOG server with a number
+ of other servers on a per-entry basis. No additional software is needed,
+ only two elogd daemons talking to each other. The synchronization can be
+ executed manually or periodically. If entries are changed/added/deleted
+ on both sides, they get merged properly during synchronization. In order
+ to minimize network traffic, each ELOG server calculates a MD5 checksum
+ for each message, which gets exchanged during synchronization. Only when
+ the MD5 checksum differs, entries are transferred.
+
+
+ To set-up mirroring, install two elogd servers on two machines (for
+ testing purpose that also works on one machine with two elogd servers
+ running on different ports). This can be done in two ways:
+
+
+ -
+ Automatic configuration
+
+ A complete elog server can be transferred to a secondary server using
+ the clone command. Assume the existing server
+ resides at http://master.your.domain/, and you
+ want to mirror this server to a new location at
+ http://slave.your.domain/. You do that by
+ installing the elog package at the slave machine, and then executing
+ on the slave:
+
+
+elogd -C http://master.your.domain
+
+
+ This command tells elogd to retrieve the configuration file, and
+ optionally all logbook entries and password files from the master
+ machine. Note that both servers must be version 2.5.4 or later. In
+ case of trouble, you can turn on verbose messaging:
+
+
+elogd -v -C http://master.your.domain
+
+
+ which could give some hints. If a logbook on the master server uses
+ restricted access, you have to specify the admin user name and
+ password. After everything has been transferred, you can start elogd
+ in the normal way.
+
+
+ -
+ Manual configuration
+
+ First, copy the elogd.cfg file from the master to the slave server.
+ Make sure that the files are identical (except the port setting if
+ you run two servers on the same machine). Then, add the following
+ configuration options. They should be put into the [global] section
+ of the cofiguration file:
+
+
+ -
+
Mirror server = <URL-list>
+
+ This statement specifies one or more mirror servers. Each URL must
+ contain the host, port and possible subdirectory of the remote
+ server, as if you would access it through your browser. A typical
+ statement looks like:
+
+ Mirror server = myhost.mydomain.org:8080,
+ http://another.server.org/elog/
+
+ The URL should not contain any logbook name, this gets added
+ automatically. The second example contains a subdirectory, which is
+ typically used if the elogd daemon runs under an Apache proxy.
+
+ -
+
Mirror config = 0 | 1
+
+ Normally, only the logbook entries are mirrored. One can also
+ mirror the contents of the elogd.cfg configuration file for
+ individual logbooks. This can be turned on by setting this option
+ to 1. Default is 0. Only
+ the individual logbook section is mirrored, not the [global]
+ section. Settings which are specific to one server, for example the
+ URL = statement, should then be kept in the
+ [global] section, so that they are not mirrored between different
+ servers.
+
+
+ -
+
Mirror cron = Minute Hour Day Month Weekday
+
+ This statement turns on periodic mirroring. The format is similar
+ to the UNIX cron command. Each of the five
+ values can either be an asterisk, which means all possible values,
+ a comma-separated list or a range. It can be explained most easily
+ with examples:
+
+
+
+ |
+ Mirror cron=
+ |
+
+ meaning
+ |
+
+
+ |
+ 0 3 * * *
+ |
+
+ Every night at 3:00
+ |
+
+
+ |
+ 30 7 1,15 * *
+ |
+
+ At 7:30 every 1st and 15th of a month
+ |
+
+
+ |
+ 0 12 10 10 *
+ |
+
+ Once a year at 12:00 on my birthday
+ |
+
+
+ |
+ 0 7-18 * * 1-5
+ |
+
+ Once every hour from 7:00 to 18:00 from Monday to Friday
+ |
+
+
+
+ Valid ranges for each value are:
+
+
+
+ |
+ Minute
+ |
+
+ 0-59
+ |
+
+
+ |
+ Hour
+ |
+
+ 0-23
+ |
+
+
+ |
+ Day
+ |
+
+ 1-31
+ |
+
+
+ |
+ Month
+ |
+
+ 1-12
+ |
+
+
+ |
+ Weekday
+ |
+
+ 0-6 with 0=Sunday, 1=Monday, etc.
+ |
+
+
+
+ If mirroring is turned on, it is advisable to use the
+ Logfile = option to turn on logging, so that
+ one can inspect the logfile to see if the mirroring works
+ correctly.
+
+
+ -
+
Mirror user = <name>
+
+ If periodic mirroring is used via the Mirror cron
+ = statement and the remote logbook uses user-level
+ access, this statement specifies the user name which is used to log
+ in to the remote logbook. The password is taken from the local
+ password file and has to match the password in the remote password
+ file, otherwise the access is not allowed. The user name is typical
+ the login name of the administrator.
+
+
+ -
+
Mirror simulate = 0 | 1
+
+ If one wants to try out mirroring without causing any harm, one can
+ turn on this flag. During synchronization, entries are compared and
+ necessary transfers are displayed, but not executed. Default is
+ 0.
+
+
+ -
+
Mirror exclude = 0 | 1
+
+ By default, all logbooks are mirrored. Individual logbooks might be
+ excluded from mirroring by putting Mirror exclude =
+ 1 in their individual logbook section of the
+ configuration file (Not the [global] section). Default is
+ 0.
+
+
+
+
+
+ If the statement Mirror server is present in the
+ configuration file, a new menu option "Synchronize"
+ appears on the elog page. Clicking on this menu options starts the
+ synchronization:
+
+
+
+ On the left side one sees the entry ID's. Entries which are equal locally
+ and remotely are not displayed. Here are the rules for
+ synchronization:
+
+
+
+ - If an entry has been modified locally but not remotely, it is
+ submitted to the remote server.
+
+ - If an entry has been modified remotely but not locally, it is
+ retrieved from the remote server and saved locally.
+
+ - If an entry has been modified remotely and locally since the last
+ synchronization, an error is shown that the entries are conflicting. In
+ that case one has to merge the entries manually and delete it on one
+ side.
+
+ - If an entry has been deleted locally, it is deleted remotely.
+
+ - If an entry has been deleted remotely, it is deleted locally.
+
+ - If a new entry exists locally, it is submitted.
+
+ - If a new entry exists remotely, it is retrieved from the remote
+ server and saved locally.
+
+ - If new entries exist locally and remotely having the same entry ID,
+ the local entries are changed to have higher entry IDs, then the remote
+ ones are retrieved. Care should be taken if external links (such as
+
elog:123) to the local entries are used, since they
+ will point afterwards to the wrong entry.
+
+
+
+ By starting the synchronization on one elogd server, this server becomes
+ the client and the other one becomes the server. This means that the
+ local server actively compares the local and the remote messages, and
+ updates one or the other if necessary. The other (remote) server does not
+ need to have any mirror option in its configuration file, since the local
+ server simulates a web browser to send and retrieve messages to the
+ remote server. It is however allowed that the remote server also contains
+ some mirror settings in the configuration file, this way the
+ synchronization can be started from both servers.
+
+
+
+
+
diff --git a/doc/download.html b/doc/download.html
index d5e4a748..d6076ce9 100755
--- a/doc/download.html
+++ b/doc/download.html
@@ -29,8 +29,8 @@ containing bug fixes or some new and not yet completely debugged code. This
is usually the case if some user asks for some new features, which are then
implemented and sent to the user for testing. The minor releases are named
x.y.z-r where r is the release number.
-A 
