From 9aa22137e2427e1f44c7fca2f30005ba8b22195d Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Wed, 25 Aug 2010 19:10:18 +0000 Subject: postgres hackery --- doc/README.mysql | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 doc/README.mysql (limited to 'doc/README.mysql') diff --git a/doc/README.mysql b/doc/README.mysql new file mode 100644 index 000000000..e123c43ac --- /dev/null +++ b/doc/README.mysql @@ -0,0 +1,95 @@ +How to setup the MySQL database for GNUnet. + +NOTE: This db module does NOT work with mysql before 4.1 since we need +prepared statements. We are generally testing the code against MySQL +5.0 at this point. + +HIGHLIGHTS + +Pros + + On up-to-date hardware where mysql can be used comfortably, this + module will have better performance than the other db choices + (according to our tests). + + Its often possible to recover the mysql database from internal + inconsistencies. The other db choices do not support repair + (gnunet-check cannot fix problems internal to the dbmgr!). + For example, we have seen several cases where power failure + has ruined a gdbm database beyond repair. + + much faster (for one of the key benchmarks -- content migration + -- we have measure mysql taking 2s for an operation where + sqlite takes 150s). +Cons + - Memory usage (Comment: "I have 1G and it never caused me trouble") + - Manual setup + +MANUAL SETUP INSTRUCTIONS + + 1) in /etc/gnunet.conf, set + sqstore = "sqstore_mysql" + + 2) Then access mysql as root, + $ mysql -u root -p + and do the following. [You should replace $USER with the username + that will be running the gnunetd process]. + + CREATE DATABASE gnunet; + GRANT select,insert,update,delete,create,alter,drop,create temporary tables + ON gnunet.* TO $USER@localhost; + SET PASSWORD FOR $USER@localhost=PASSWORD('$the_password_you_like'); + FLUSH PRIVILEGES; + + 3) In the $HOME directory of $USER, create a ".my.cnf" file + with the following lines + + [client] + user=$USER + password=$the_password_you_like + + Thats it. Note that .my.cnf file is a security risk unless its on + a safe partition etc. The $HOME/.my.cnf can of course be a symbolic + link. Even greater security risk can be achieved by setting no + password for $USER. Luckily $USER has only priviledges to mess + up GNUnet's tables, nothing else (unless you give him more, + of course). + + 4) Still, perhaps you should briefly try if the DB connection + works. First, login as $USER. Then use, + + $ mysql -u $USER + mysql> use gnunet; + + If you get the message "Database changed" it probably works. + + [If you get "ERROR 2002: Can't connect to local MySQL server + through socket '/tmp/mysql.sock' (2)" it may be resolvable by + "ln -s /var/run/mysqld/mysqld.sock /tmp/mysql.sock" + so there may be some additional trouble depending on your mysql setup.] + + 5) If you want to run the testcases, you must create a second + database "gnunetcheck" with the same username and password. + This database will then be used for testing ("make check"). + + +REPAIRING TABLES + +- Its probably healthy to check your tables for inconsistencies + every now and then, especially after system crashes. +- If you get odd SEGVs on gnunetd startup, it might be that the mysql + databases have been corrupted. +- The tables can be verified/fixed in two ways; + 1) by shutting down mysqld (mandatory!) and running + # myisamchk -r *.MYI + in /var/lib/mysql/gnunet/ (or wherever the tables are stored). + Another repair command is "mysqlcheck". The usable command + may depend on your mysql build/version. Or, + 2) by executing + mysql> REPAIR TABLE gn090; + + +PROBLEMS? + +If you have problems related to the mysql module, your best friend is +probably the mysql manual. The first thing to check is that mysql is +basically operational, that you can connect to it, create tables, +issue queries etc. + -- cgit v1.2.3