LON-CAPA User Help: Server System Administration LON-CAPA User Help : Server System Administration Installation and maintenance of a LON-CAPA server. + Subcategories: + <(*) (missing or broken file) + + Answers in this category: + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + <(*) (missing or broken file) + LON-CAPA User Help : Server System Administration : CVS CVS + Subcategories: + + Answers in this category: + <(*) (missing or broken file) + LON-CAPA User Help : Server System Administration : CVS : CVS info (All examples below assume your cvs checkout is in /somewhere/loncapa)Send an e-mail to to make the change to use :ext recursively. Updating the repository To update a repository to have the files marked STABLE do this: $ cd /somewhere/loncapa $ cvs update -d -r STABLE It is expected that all production machines will be using this. To change a repository to have the latest (and maybe greatest versions) do this: $ cd /somewhere/loncapa $ cvs update -d -A It is expected that all developers to be using this. If you have updated a repository to the Latest (and as it turns out not so great) version, doing: $ cd /somewhere/loncapa $ cvs update -d -r STABLE Will take you back to the STABLE version. A refresher on how to upgrade your machine: export CVS_RSH=ssh export CVSROOT=:ext:USERNAME@source.lon-capa.org:/home/cvs cd loncapa cvs update -d -r STABLE cd loncom/build su make install make configinstall /etc/rc.d/init.d/httpd restart /etc/rc.d/init.d/loncontrol restart Using a public key The downside to using ssh for remote authentication in place of pserver is that you will be prompted to enter your password each time you issue a cvs command. A solution to this is to use $ ssh-keygen -t dsa to generate public and private keys in ~/.ssh/ Send the public key (id_dsa.pub) to helpdesk@lon-capa.org so it can be added to the appropriate authorized_keys file on source.lon-capa.org If you have any problems or questions please contact me. -- Stuart Raeburn helpdesk@lon-capa.org LON-CAPA User Help : Server System Administration : How do I install LON-CAPA? Installation instructions are maintained at http://install.lon-capa.org/docs/install/index.html. LON-CAPA User Help : Server System Administration : What hardware does LON-CAPA require? Hardware Recommendation ----------------------- For full-time, classroom usage, an adequate LON-CAPA server should be/have: * a multiprocessor machine, * a CPU speed of 1 gigahertz, * a gigabyte of memory, * and at least 40 to 80 gigabytes of hard disk space. A lesser machine can be used for toying around with LON-CAPA (LON-CAPA will run for a single user on most any machine). LON-CAPA servers experience significant peaks of activity before a homework submission deadline. To support these critical peaks of activity, it is strongly advised that LON-CAPA machines fit the above recommendation. If thousands of students start accessing the box as a web server... well you may want to consider more options. The design of the LON-CAPA system is to naturally and transparently load-balance on multiple computer clusters. So, a simple solution for running an entire college campus is to just have an adequate plurality of LON-CAPA servers rather than a single, particularly monstrous server. We like to think of high web server usage as "a good problem" though.. :) More Information on Hardware and System Administration ------------------------------------------------------ I find that LON-CAPA works nicely (for development purposes) on a Pentium II, 20 gigabytes of hard-disk space, 256M RAM, and 400MHz. The consensus is though, that this may only be adequate for a class of a dozen students. If you are making a serious investment, we suggest you join our mailing list by visiting http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin By posting to this mailing list, you can learn about what solutions have worked for others. We support Linux OS. LON-CAPA has been shown to work on Debian, Mandrake, and RedHat. Instructions are based on RedHat-centric installs. Given the current level of new LON-CAPA feature requests and frequency of new software versions, we suggest that you stick with RedHat to reduce high-frequency system administration overhead. LON-CAPA User Help : Server System Administration : What should I never do? NEVER EVER EVER install the LON-CAPA-setup rpm on a running system. LON-CAPA User Help : Server System Administration : What are the links to check out how my system is running? http://MACHINENAME/lon-status/index.html http://MACHINENAME/lon-status/filestatus.html (CVS-> make statuspost) http://MACHINENAME/lon-status/rpmstatus.html (CVS-> make rpmstatuspost) LON-CAPA User Help : Server System Administration : Can reducing the number of servers in hosts.tab increase efficiency of my server? No. The network connections (lonc/lond) created by hosts.tab place a very low load on the server which does not greatly interfere with memory usage and the CPU rate. The only potential efficiency problem that might result is the introduction of poorly configured/updated LON-CAPA machines in the network (bad lonc/lond software)--causing servers to have their Apache web server children wait on various network request (the Apache child will go on with life, but it is inefficient while it is waiting to timeout the lonc/lond connection). There is great importance attached to this issue right now. The research and development arm of LON-CAPA is currently implementing these further solutions: * lonc/lond connections are dynamically brought up and down based off of the timeout field and the maximum number of connections fields in hosts.tab * the upgrade process will test the lonc/lond layer * hosts.tab will be automatically updated and with this automatic update, there will be testing of the lonc/lond connections LON-CAPA User Help : Server System Administration : How do I SAFELY upgrade from RedHat 6.2 to RedHat 7.2? You should only upgrade from RedHat 6.2 to RedHat 7.2 if you are an experienced Linux System Administrator. 1. Backing up 2. Upgrade to RedHat 7.2 3. Secure your machine 4. Download stable LON-CAPA release 5. Check the status of your RPMs 6. Additional RPMs to download 7. Recheck the status of your RPMs 8. Updating your kernel 9. Install LON-CAPA 10. Set up MySQL and systemperl. ################## # 1. Backing up. # ################## There are two things that you must, by all costs, save. **** All the files in the /home directory. (NOTE: You will not be able to save the /home/httpd/sockets directory) **** Your machine's configuration. I recommend you print out: /etc/hostname /etc/hosts /etc/resolv.conf /etc/httpd/conf/access.conf /etc/httpd/conf/loncapa.conf and any other files described at http://install.lon-capa.org/reconfig/. ############################ # 2. Upgrade to RedHat 7.2 # ############################ Here are two helpful links: http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/install-guide/ http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/pdf/rhl-ig-x86-en-72.pdf ########################## # 3. Secure your machine # ########################## Do the following: echo "ALL: PARANOID" > /etc/hosts.deny Make any other modifications to your /etc/hosts.allow and /etc/hosts.deny. The next goal is to update all of your RPMs as quickly as possible (to avoid a network break-in. Ideally, you would not be connected to the network and would have downloaded/burned onto CD-R's the contents of: ftp://mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/i386 ftp://mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/i486 ftp://mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/i586 ftp://mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/i686 ftp://mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/noarch Otherwise, you need to first ethernet configure your computer. ####################################### # 4. Download stable LON-CAPA release # ####################################### This is still done with CVS. Please consult: http://install.lon-capa.org/docs_old/cvsupgrade/ #################################### # 5. Check the status of your RPMs # #################################### cd loncapa/loncom/build perl check-rpms -ftp mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/ -d /home/user/install --no-kernel --download cd /home/user/install rpm -Uvh *.rpm should be a fairly straight shot (you may need a few more additional RPMs from ftp://mirror.pa.msu.edu/linux/redhat/redhat-7.2-en/os/i386/RedHat/RPMS/.) ################################## # 6. Additional RPMs to download # ################################## Compare the RPMs on your system (rpm -qa) with loncapa/doc/otherfiles/rpm_list.txt ###################################### # 7. Recheck the status of your RPMs # ###################################### Recheck the status of your RPMs one more time. perl check-rpms -ftp mirror.pa.msu.edu/linux/redhat/linux/updates/7.2/en/os/ -d /home/user/install --no-kernel --download ########################### # 8. Updating your kernel # ########################### Follow the instructions at: http://www.redhat.com/support/resources/howto/kernel-upgrade/ Note: If you fail with the kernel update, you will have to: * insert a RedHat 7.2 Disc #1 * Type "linux rescue" at the boot prompt * and try to make fixes onto the filesystem ####################### # 9. Install LON-CAPA # ###################### Please see http://install.lon-capa.org/; especially http://install.lon-capa.org/docs_old/cvsupgrade/ The goal is to run: make install ################################### # 10. Set up MySQL and systemperl # ################################### See loncapa/doc/how_to_install_on_RedHat7.2.txt LON-CAPA User Help : Server System Administration : RedHat 7.2 install is missing files lib_perl.so, libncurses.so, etc. To find out what RPMs correspond with the missing files libncurses, libreadline, libperl.so, you can often do a google search, for instance "rpm libncurses.so" will tell you to try the ncurses4 or ncurses RPM. libreadline is either the readline or readline2 rpm. libperl.so is part of the mod_perl rpm. All these rpms are available at: ftp://mirror.pa.msu.edu/linux/redhat/redhat-7.2-en/os/i386/RedHat/RPMS/ LON-CAPA User Help : Server System Administration : How do I configure the MySQL server? lonSqlAccess inside loncapa_apache.conf should always be set to value 'localhostkey' This is the password for www@localhost on the MySQL database as described in the instructions below. RedHat 7.* requires these RPMs: * mysql-3.23.41-1 (or standard RedHat 7.* version) * mysql-server-3.23.41 (or standard RedHat 7.* version) RedHat 6.* requires the RPM: * LON-CAPA-mysql available at http://install.lon-capa.org/3.1/latestRPMS/. DUE TO COMPATIBILITY PROBLEMS, PLEASE DO NOT USE RPMs FROM OTHER SOURCES SUCH AS www.mysql.com. Enter the mysql shell--- (use one of the following two commands) bash$ mysql -u root mysql bash$ mysql -u root -p mysql Run these commands--- mysql> CREATE DATABASE loncapa; mysql> INSERT INTO user (Host, User, Password) mysql> VALUES ('localhost','www',password('localhostkey')); mysql> GRANT ALL PRIVILEGES ON *.* TO www@localhost; mysql> FLUSH PRIVILEGES; mysql> SET PASSWORD FOR root@localhost=PASSWORD('new_password'); If you need to change the www@localhost password, then bash$ mysql -u root -p mysql mysql> SET PASSWORD FOR www@localhost=PASSWORD('localhostkey'); LON-CAPA User Help : Server System Administration : When I restart the web server, there are errors about missing perl files? What can be done? This is most likely due to missing files that are supposed to be inside the /usr/lib/perl5 directory tree. You can refresh your /usr/lib/perl5 directory tree (and make sure it is up to date with everything LON-CAPA needs) by 1) Going to http://install.lon-capa.org/3.1/latestRPMS/ 2) Downloading LON-CAPA-systemperl-*.*-1.i386.rpm if you are on RedHat 6.* or LON-CAPA-systemperl-*.*-rh72.i386.rpm if you are on RedHat 7.* 3) Install the files with the 'rpm' command: rpm -Uvh --nodeps --force LON-CAPA-systemperl-*.i386.rpm *** Debian users only, see below *** You should consult CVS:doc/otherfiles/perl_modules.txt and manually install needed perl modules from http://www.cpan.org/. LON-CAPA User Help : Server System Administration : What is a LON-CAPA domain? A LON-CAPA domain is a collection of load-balancing institutional machines forming a cluster of LON-CAPA servers. It has nothing to do with the many other meanings for the word "domain", such as "domain names" like "loncapa.org", or Windows file server domains. If you are installing a LON-CAPA server for testing purposes, it is safe to create your own domain name for testing. You should ask the person running a real domain before adding your computer to their domain. LON-CAPA User Help : Server System Administration : What are all of the LON-CAPA configuration values? Expiration Cache Time? Server Load? Machine ID? LON-CAPA Domain? LON Host ID ("Machine Name") is an internal ID within the LON-CAPA network used to specify the uniqueness of a particular LON-CAPA server. LON System Administrator E-Mail specifies the e-mail address of an institutional member responsible for direct upkeep of this server. LON Domain ("Domain Name") is a unique internal identifier within the LON-CAPA network specific to the home institution; A LON-CAPA domain is a collection of load-balancing institutional machines forming a cluster of LON-CAPA servers. It has nothing to do with the many other meanings for the word "domain", such as "domain names" like "loncapa.org", or Windows file server domains. If you are installing a LON-CAPA server for testing purposes, it is safe to create your own domain name for testing. You should ask the person running a real domain before adding your computer to their domain. LON Load Limit ("Server Load") specifies a threshold of activity within The LearningOnline Network that this machine should provide. We strongly recommend a value of 2.00. Depending on processor architecture (dual processor), this value may be increased, but there is no readily available measure in this regard. Cache Expiration Time indicates, in seconds, how long distributed resources should be held in the server's cache when not being accessed by students, instructors, or any other class of user. LON-CAPA User Help : Server System Administration : What ports does a LON-CAPA system need open? LON-CAPA requires that ports 5663, 8080 and 80 be open in order for loncapa to work. 5663 is used to implement a TCP/IP courseware management trafficking layer on the distributed network system (educational resource data is passed, user information is handled, etc). 8080, necessary for logging in, is used to deliver auxiliary web content (e.g. icons). 80 is used for standard http data. While you can probably alter 80 to another port, 8080 and 5663 are currently hard-coded. Whereas 5663 is the uniform standard across all other LON-CAPA servers, it is unchangeable. You probably want port 22 (ssh) open. You may also wish to open other ports for nfs/samba etc. Leaving port 25 open, would also be a good idea as we plan for Lon-CAPA to receive email in the future. LON-CAPA User Help : Server System Administration : RedHat 8.0 Tips I (sharrison@users.sourceforge.net) do not currently plan a specific set of instructions and customized installation for RedHat 8.0. I am, however, working on RedHat 8.0 in order to prepare for the future (e.g. RedHat 8.1, 8.2, or 8.3). For more information, please visit: http://bugs.lon-capa.org/show_bug.cgi?id=856 LON-CAPA User Help : Server System Administration : New Item LON-CAPA User Help : Server System Administration : How can I tell if load-balancing is working between the servers listed in /home/httpd/lonTabs/spare.tab? Overload the machine and then try logging in. You should end up on a different machine. This might be done (on a server which is not currently in production demand) by changing the server load parameter which, when exceeded, will trigger the attempt to use an alternate server. To change the server load which will trigger load balancing to another server adjust the following parameter /etc/httpd/conf/loncapa.conf PerlSetVar lonLoadLim 2.00 2 is default, could be higher on a busy library server. Set it low to test out load balancing. (After changing tha loncapa.conf lonLoadLim parameter, you will need to restart httpd) [batchelo@sfu.ca] + Subcategories: + + Answers in this category: + LON-CAPA User Help : Server System Administration : How Transparent is Load-balancing to the users? Nearly transparent. If they log-in to one server and it decides it is overloaded, it will ask the other servers for their load measures. If an alternate server isn't overloaded, the only change the student should notice is that the URL is now changed. Otherwise everything should look and act the same. Load balancing is done when logging in and at no other time. Once logged in the user does not shift between machines. [batchelo@sfu.ca] This document is at: http://help.loncapa.org/cgi-bin/fom?file=4 Generated by FAQ-O-Matic 2.719, available at http://faqomatic.sourceforge.net/