Annotation of doc/build/loncapasqldatabase.html, revision 1.19
1.1 harris41 1: <HTML>
2: <HEAD>
3: <TITLE>LON-CAPA SQL Database Documentation</TITLE>
4: </HEAD>
5: <BODY>
6: <H1>LON-CAPA SQL Database Documentation</H1>
7: <P>
8: Scott Harrison
9: </P>
10: <P>
1.12 harris41 11: Last updated: 02/15/2001
1.1 harris41 12: </P>
1.2 harris41 13: <P>
1.1 harris41 14: This file describes issues associated with LON-CAPA
15: and a SQL database.
16: </P>
1.5 harris41 17: <H2>Latest HOWTO</H2>
1.2 harris41 18: <P>
1.4 harris41 19: <UL>
1.9 harris41 20: <LI>Important notes
1.4 harris41 21: <LI>Current status of documentation</LI>
22: <LI>Current status of implementation</LI>
23: <LI>Purpose within LON-CAPA</LI>
1.8 harris41 24: <LI>Dependencies</LI>
1.4 harris41 25: <LI>Installation</LI>
26: <LI>Installation from source</LI>
27: <LI>Configuration (automated)</LI>
28: <LI>Manual configuration</LI>
29: <LI>Testing</LI>
30: <LI>Example sections of code relevant to LON-CAPA</LI>
31: </UL>
32: </P>
1.9 harris41 33: <H2>Important notes</H2>
34: <P>
1.12 harris41 35: The current database is implemented assuming a non-adjustable
36: architecture involving these data fields (specific to each version
37: of a resource).
38: <UL>
39: <LI>title</LI>
40: <LI>author</LI>
41: <LI>subject</LI>
42: <LI>notes</LI>
43: <LI>abstract</LI>
44: <LI>mime</LI>
45: <LI>language</LI>
46: <LI>creationdate</LI>
47: <LI>lastrevisiondate</LI>
48: <LI>owner</LI>
49: <LI>copyright</LI>
50: </UL>
51: </P>
52: <P>
1.14 harris41 53: Security occurs as a function of the user 'www',
54: and the permissions on the files in the /usr/local/mysql
55: directory. (These files and directories should
56: be 700, 600, 500, 400, etc; not allow access to anyone
57: but user 'www'.)
58: </P>
59: <P>
1.12 harris41 60: These commands create the loncapameta database.
61: <PRE>
1.13 harris41 62: mysql> CREATE DATABASE IF NOT EXISTS loncapa;
63: mysql> USE loncapa;
1.16 harris41 64: mysql> CREATE TABLE IF NOT EXISTS metadata (title TEXT, author TEXT, subject TEXT, url TEXT, keywords TEXT, version TEXT, notes TEXT, abstract TEXT, mime TEXT, language TEXT, creationdate DATETIME, lastrevisiondate DATETIME, owner TEXT, copyright TEXT, FULLTEXT idx_title (title), FULLTEXT idx_author (author), FULLTEXT idx_subject (subject), FULLTEXT idx_url (url), FULLTEXT idx_keywords (keywords), FULLTEXT idx_version (version), FULLTEXT idx_notes (notes), FULLTEXT idx_abstract (abstract), FULLTEXT idx_mime (mime), FULLTEXT idx_language (language), FULLTEXT idx_owner (owner), FULLTEXT idx_copyright (copyright)) TYPE=MYISAM;
65: mysql> INSERT INTO metadata VALUES ('The Structure of Scientific Revolutions','Thomas S. Kuhn','scientific philosophy','/res/msu/shh1/poobah2.html','aphorisms, theories, paradigm, revolution','current','still developing','This famous book stands out in contrast to the more rigid theories of Popper.','html','seniso','1999-03-03 12:34:56','1999-03-03 3:12:00','shh1@msu.edu','default');
1.13 harris41 66: mysql> SELECT * FROM metadata WHERE title REGEXP "1";
67: </PRE>
68: </P>
69: <P>
70: Current time values for things.
71: <PRE>
72: fenchurch.lite.msu.edu
73: Mem: 46812K av, 45632K used, 1180K free, 14756K shrd, 4292K buff
74: Swap: 1148608K av, 11260K used, 1137348K free 13244K cached
1.12 harris41 75:
1.13 harris41 76: Red Hat Linux release 6.2 (Zoot)
77: Kernel 2.2.16-3 on an i586
1.12 harris41 78: </PRE>
1.13 harris41 79: <BR>Q: How big are data records in test database? A: on average, 1000 bytes each, medline records from PubMed.
80: <BR>Q: How big is the biggest field? A: on average, 838 bytes each
81: <BR>Q: How much time to insert 5284 medline records into database?
82: A: 600 seconds
83: <BR>Q: What about when using "speed-technique" on page 130? A: 689 seconds (weird, eh?)
84: <BR>Q: What about REGEXP searching? A: about 1-2 seconds for small fields;
85: 10 to 20 seconds for REGEXP search on "abstract" field
86: <BR>Q: What about FULLTEXT indexing? A: about 6 seconds for abstract field.
87:
1.12 harris41 88: </P>
89: <P>
90: An important quote from the manual:
91: <BLOCKQUOTE>
92: In MySQL Version 3.23.23 or later, you can also create special FULLTEXT indexes. They are used for full-text search. Only the MyISAM table type supports FULLTEXT indexes. They can be created only from
93: VARCHAR and TEXT columns. Indexing always happens over the entire column and partial indexing is not supported. See section 25.2 MySQL Full-text Search for details.
94: </BLOCKQUOTE>
95: </P>
96: <P>
97: I plan on using a MyISAM table type with 11 metadata fields of column
98: type=TEXT.
99: </P>
100: <P>
1.9 harris41 101: It might be worthwhile to look at /usr/local/mysql/manual.html.
102: It is quite in depth.
103: </P>
1.5 harris41 104: <H2>Current status of documentation</H2>
1.4 harris41 105: <P>
1.2 harris41 106: I am going to begin documentation by inserting what notes
107: I have into this file. I will be subsequently rearranging
1.4 harris41 108: them and editing them based on the tests that I conduct.
1.2 harris41 109: I am trying to make sure that documentation, installation,
110: and run-time issues are all consistent and correct. The
111: current status of everything is that it works and has
112: been minimally tested, but things need to be cleaned up
113: and checked again!
114: </P>
1.5 harris41 115: <H2>Current status of implementation</H2>
1.4 harris41 116: <P>
1.6 harris41 117: Need to
118: <UL>
119: <LI>Installation: Fix binary file listings for user permissions and ownership.
120: <LI>Installation: Make sure sql server starts, and if database does not
121: exist, then create. (/etc/rc.d).
122: <LI>Processes: Make sure loncron initiates lonsql on library machines.
123: <LI>Read in metadata from right place periodically.
124: <LI>Implement tested perl module handler.
125: </UL>
126: <P>
1.4 harris41 127: Right now, a lot of "feasibility" work has been done.
128: Recipes for manual installation and configuration have
129: been gathered. Network connectivity of lond->lonsql->lond->lonc
130: type tests have been performed. A binary installation
1.7 harris41 131: has been compiled in an RPM (LON-CAPA-mysql, with perl components
132: a part of LON-CAPA-systemperl).
1.4 harris41 133: The most lacking test in terms of feasibility has
134: been looking at benchmarks to analyze the load at which
135: the SQL database can efficiently allow many users to
136: make simultaneous requests of the metadata database.
137: </P>
138: <P>
139: Documentation has been pieced together over time. But,
140: as mentioned in the previous section, it needs an
141: overhaul.
142: </P>
143: <P>
144: The binary installation has some quirks associated with it.
145: Some of the user permissions are wrong, although this is
146: benign. Also, other options of binary installation (such
147: as using binary RPMs put together by others) were dismissed
148: given the difficulty of getting differing combinations of
149: these external RPMs to work together.
150: </P>
151: <P>
152: Most configuration questions have been initially worked out
153: to the point of getting this SQL software component working,
154: however there may be more optimal approaches than currently
155: exist.
156: </P>
1.5 harris41 157: <H2>Purpose within LON-CAPA</H2>
1.4 harris41 158: <P>
159: LON-CAPA is meant to distribute A LOT of educational content
160: to A LOT of people. It is ineffective to directly rely on contents
161: within the ext2 filesystem to be speedily scanned for
162: on-the-fly searches of content descriptions. (Simply put,
163: it takes a cumbersome amount of time to open, read, analyze, and
164: close thousands of files.)
165: </P>
166: <P>
167: The solution is to hash-index various data fields that are
168: descriptive of the educational resources on a LON-CAPA server
169: machine. Descriptive data fields are referred to as
170: "metadata". The question then arises as to how this metadata
171: is handled in terms of the rest of the LON-CAPA network
172: without burdening client and daemon processes. I now
173: answer this question in the format of Problem and Solution
174: below.
175: </P>
176: <P>
177: <PRE>
178: PROBLEM SITUATION:
179:
180: If Server A wants data from Server B, Server A uses a lonc process to
181: send a database command to a Server B lond process.
182: lonc= loncapa client process A-lonc= a lonc process on Server A
183: lond= loncapa daemon process
184:
185: database command
186: A-lonc --------TCP/IP----------------> B-lond
187:
188: The problem emerges that A-lonc and B-lond are kept waiting for the
189: MySQL server to "do its stuff", or in other words, perform the conceivably
190: sophisticated, data-intensive, time-sucking database transaction. By tying
191: up a lonc and lond process, this significantly cripples the capabilities
192: of LON-CAPA servers.
193:
194: While commercial databases have a variety of features that ATTEMPT to
195: deal with this, freeware databases are still experimenting and exploring
196: with different schemes with varying degrees of performance stability.
197:
198: THE SOLUTION:
199:
200: A separate daemon process was created that B-lond works with to
201: handle database requests. This daemon process is called "lonsql".
202:
203: So,
204: database command
205: A-lonc ---------TCP/IP-----------------> B-lond =====> B-lonsql
206: <---------------------------------/ |
207: "ok, I'll get back to you..." |
208: |
209: /
210: A-lond <------------------------------- B-lonc <======
211: "Guess what? I have the result!"
212:
213: Of course, depending on success or failure, the messages may vary,
214: but the principle remains the same where a separate pool of children
215: processes (lonsql's) handle the MySQL database manipulations.
216: </PRE>
217: </P>
1.8 harris41 218: <H2>Dependencies</H2>
219: <P>
220: I believe (but am not 100% confident) that the following
221: RPMs are necessary (in addition to the current ones
222: in rpm_list.txt) to run MySQL. Basically I discovered these
223: dependencies while trying to do external RPM based installs.
224: I assume, and sometimes found, that these dependencies apply
225: to tarball-based distributions too. (So to play it on the
226: safe side, I am going to include these RPMs as part of the
227: core, minimal RPM set.)
228: <UL>
229: <LI>egcs-1.1.2-30</LI>
230: <LI>cpp-1.1.2-30</LI>
231: <LI>glibc-devel-2.1.3-15</LI>
232: <LI>zlib-devel-1.1.3-6</LI>
233: </UL>
234: </P>
1.5 harris41 235: <H2>Installation</H2>
1.4 harris41 236: <P>
237: Installation of the LON-CAPA SQL database normally occurs
238: by default when using the LON-CAPA installation CD
239: (see http://install.lon-capa.org). It is installed
240: as the LON-CAPA-mysql RPM. This RPM encodes for the MySQL
1.7 harris41 241: engine. Related perl interfaces (Perl::DBI, Perl::Msql-Mysql)
242: are encoded in the LON-CAPA-systemperl RPM.
1.4 harris41 243: </P>
244: <P>
245: The three components of a MySQL installation for the
246: LON-CAPA system are further described immediately below.
247: <TABLE BORDER="0">
248: <TR><TD COLSPAN="2"><STRONG>Perl::DBI module</STRONG>-
249: the API "front-end"...</TD></TR>
250: <TR><TD WIDTH="10%"></TD><TD>database interface module for organizing generic
251: database commands which are independent of specific
252: database implementation (such as MySQL, mSQL, Postgres, etc).
253: </TD></TR>
254: <TR><TD COLSPAN="2"><STRONG>Perl::MySQL module</STRONG>-
255: the API "mid-section"...</TD></TR>
256: <TR><TD WIDTH="10%"></TD><TD>the module to directly interface with the actual
257: MySQL database engine</TD></TR>
258: <TR><TD COLSPAN="2"><STRONG>MySQL database engine</STRONG>-
259: the "back-end"...</TD></TR>
260: <TR><TD WIDTH="10%"></TD><TD>the binary installation (compiled either
261: from source or pre-compiled file listings) which provides the
262: actual MySQL functionality on the system</TD></TR>
263: </TABLE>
264: </P>
1.5 harris41 265: <H2>Installation from source</H2>
1.4 harris41 266: <P>
1.8 harris41 267: Note: the mysql site recommends that Linux users install by
268: using the MySQL RPMs (MySQL-client, MySQL, MySQL-shared, etc).
269: While these RPMs work, I was unsuccessful at integrating
270: this RPM-installed database with perl modules from www.cpan.org.
271: Hence, I <STRONG>strongly</STRONG> recommend that, when installing
272: from "source", MySQL and the perl components be in fact installed
273: from their tarballs (.tar.gz, .tgz). (Perl components, when installed
274: from RPMs, also wound up in incorrect locations on the disk.)
275: Do not coordinate a source install with externally made RPMs!
276: It is, of course, okay to use LON-CAPA RPMs such as LON-CAPA-systemperl
277: and LON-CAPA-mysql since we, in fact, made these RPMs correctly :).
278: <UL>
279: <LI>http://www.cpan.org/authors/id/JWIED/Msql-Mysql-modules-1.2215.tar.gz
280: <BR>This tarball Released 20th August 2000
281: <LI>http://www.mysql.com/Downloads/MySQL-3.23/mysql-3.23.33-pc-linux-gnu-i686.tar.gz
282: <BR>This tarball Last changed 2000-11-11
283: <BR>This is actually a binary tarball (as opposed to source code
284: that is subsequently compiled).
1.9 harris41 285: <LI>http://www.cpan.org/authors/id/TIMB/DBI-1.14.tar.gz
286: <BR>This tarball Released 14th June 2000
1.8 harris41 287: </UL>
1.9 harris41 288: </P>
289: <P>So, here is exactly how I installed MySQL-3.23. (Note that all files
290: wind up in /usr/local/mysql-3.23.33-pc-linux-gnu-i686 except for
291: a link from /usr/local/mysql to /usr/local/mysql-3.23.33-pc-linux-gnu-i686
292: and some files involved in system process handling (/etc/rc.d/*/*mysql).
1.11 harris41 293: <PRE>
294: (As user=root)
295: cd /usr/local/;
296: tar xzvf mysql-3.23.33-pc-linux-gnu-i686.tar.gz
297: ln -s /usr/local/mysql-3.23.33-pc-linux-gnu-i686 mysql
298: cd /usr/local/mysql
299: chown -R www /usr/local/mysql/.
300: chgrp -R users /usr/local/mysql/.
301: chmod -R g-w,g-r,g-x /usr/local/mysql/.
302: (probably also want chmod -R a-w,a-r,a-x /usr/local/mysql/.)
303:
304: Alter <TT>safe_mysqld</TT>
305: and <TT>support-files/mysql.server</TT> to use 'localhosts' instead
306: of `bin/hostname`. Also, to use user 'www' instead of 'mysql'.
307:
308: (These changes could be done with /etc/my.cnf, but
309: I think this approach makes sure the database NEVER
310: gets screwed up due to somebody forgetting to install /etc/my.cnf).
311:
312: Change this line in mysql.server from
313: pid_file=$datadir/`@HOSTNAME@`.pid
314: to
315: pid_file=$datadir/localhost.pid
316:
317: Change this line in safe_mysqld from
318: user=root
319: to
320: user=www
321:
322: Change this line in safe_mysqld from
323: pid_file=$DATADIR/`/bin/hostname`.pid
324: to
325: pid_file=$DATADIR/localhost.pid
326:
327: Change this line in safe_mysqld from
328: test -z "$err_log" && err_log=$DATADIR/`/bin/hostname`.err
329: to
330: test -z "$err_log" && err_log=$DATADIR/localhost.err
331:
332: cp -p support-files/mysql.server /etc/rc.d/init.d/mysql
333: chmod 755 /etc/rc.d/init.d/mysql
334: /sbin/chkconfig --add mysql
335: /etc/rc.d/init.d/mysql start
336:
337: </PRE>
1.9 harris41 338: </P>
339: <P>This is how I installed the Msql-Mysql-modules perl modules.
340: <PRE>
341: [root@fenchurch Msql-Mysql-modules-1.2215]# perl Makefile.PL
342: Which drivers do you want to install?
343:
344: 1) MySQL only
345: 2) mSQL only (either of mSQL 1 or mSQL 2)
346: 3) MySQL and mSQL (either of mSQL 1 or mSQL 2)
347:
348: 4) mSQL 1 and mSQL 2
349: 5) MySQL, mSQL 1 and mSQL 2
350:
351: Enter the appropriate number: [3] 1
352:
353:
354: Do you want to install the MysqlPerl emulation? You might keep your old
355: Mysql module (to be distinguished from DBD::mysql!) if you are concerned
356: about compatibility to existing applications! [y] n
1.10 harris41 357: Where is your MySQL installed? Please tell me the directory that
358: contains the subdir 'include'. [/usr/local/mysql]
359: Which database should I use for testing the MySQL drivers? [test]
360: On which host is database test running (hostname, ip address
361: or host:port) [localhost]
1.11 harris41 362: User name for connecting to database test? [undef]
363: Password for connecting to database test? [undef]
1.9 harris41 364: [root@fenchurch Msql-Mysql-modules-1.2215]# make
365: [root@fenchurch Msql-Mysql-modules-1.2215]# make test
366: make[1]: Entering directory `/home/user/Msql-Mysql-modules-1.2215/mysql'
367: make[1]: Leaving directory `/home/user/Msql-Mysql-modules-1.2215/mysql'
368: make[1]: Entering directory `/home/user/Msql-Mysql-modules-1.2215/mysql'
369: PERL_DL_NONLAZY=1 /usr/bin/perl -I../blib/arch -I../blib/lib -I/usr/lib/perl5/5.00503/i386-linux -I/usr/lib/perl5/5.00503 -e 'use Test::Harness qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
370: t/00base............ok
371: t/10dsnlist.........ok
372: t/20createdrop......ok
373: t/30insertfetch.....ok
374: t/40bindparam.......ok
375: t/40blobs...........ok
376: t/40listfields......ok
377: t/40nulls...........ok
378: t/40numrows.........ok
379: t/50chopblanks......ok
380: t/50commit..........ok
381: t/60leaks...........skipping test on this platform
382: t/ak-dbd............ok
383: t/akmisc............ok
384: t/dbdadmin..........ok
385: t/mysql.............ok
386: t/mysql2............ok
387: All tests successful, 1 test skipped.
388: Files=17, Tests=732, 40 wallclock secs (15.38 cusr + 1.30 csys = 16.68 CPU)
389: [root@fenchurch Msql-Mysql-modules-1.2215]# make install
390:
391: These files are installed.
392: /usr/bin/dbimon
393: /usr/lib/perl5/man/man3/Bundle::DBD::mysql.3
394: /usr/lib/perl5/man/man3/DBD::mysql.3
395: /usr/lib/perl5/man/man3/Mysql.3
396: /usr/lib/perl5/site_perl/5.005/i386-linux/Bundle/DBD/mysql.pm
397: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/mysql.pm
398: /usr/lib/perl5/site_perl/5.005/i386-linux/Mysql.pm
399: /usr/lib/perl5/site_perl/5.005/i386-linux/Mysql/Statement.pm
400: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBD/mysql/mysql.bs
401: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBD/mysql/mysql.so
402: /usr/man/man1/dbimon.1
403: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/Msql-Mysql-modules/.packlist
404: </PRE>
405: </P>
406: <P>
407: This is how I installed the DBI perl modules.
1.15 harris41 408: <PRE>$dbh
1.9 harris41 409: [root@fenchurch DBI-1.14]# perl Makefile.PL
410: *** Note:
411: The optional PlRPC-modules (RPC::PlServer etc) are not installed.
412: If you want to use the DBD::Proxy driver and DBI::ProxyServer
413: modules, then you'll need to install the RPC::PlServer, RPC::PlClient,
414: Storable and Net::Daemon modules. The CPAN Bundle::DBI may help you.
415: You can install them any time after installing the DBI.
416: You do *not* need these modules for typical DBI usage.
417:
418: Optional modules are available from any CPAN mirror, in particular
419: http://www.perl.com/CPAN/modules/by-module
420: http://www.perl.org/CPAN/modules/by-module
421: ftp://ftp.funet.fi/pub/languages/perl/CPAN/modules/by-module
422:
423: Checking if your kit is complete...
424: Looks good
425: Writing Makefile for DBI
426:
427: Remember to actually *read* the README file!
428: Use 'make' to build the software (dmake or nmake on Windows).
429: Then 'make test' to execute self tests.
430: Then 'make install' to install the DBI and then delete this working
431: directory before unpacking and building any DBD::* drivers.
432:
433: [root@fenchurch DBI-1.14]# make
434: [root@fenchurch DBI-1.14]# make test
435: PERL_DL_NONLAZY=1 /usr/bin/perl -Iblib/arch -Iblib/lib -I/usr/lib/perl5/5.00503/i386-linux -I/usr/lib/perl5/5.00503 -e 'use Test::Harness qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
436: t/basics............ok
437: t/dbidrv............ok
438: t/examp.............ok
439: t/meta..............ok
440: t/proxy.............skipping test on this platform
441: t/shell.............ok
442: t/subclass..........ok
443: All tests successful, 1 test skipped.
444: Files=7, Tests=179, 7 wallclock secs ( 6.46 cusr + 0.49 csys = 6.95 CPU)
445: PERL_DL_NONLAZY=1 /usr/bin/perl -Iblib/arch -Iblib/lib -I/usr/lib/perl5/5.00503/i386-linux -I/usr/lib/perl5/5.00503 test.pl
446: test.pl
1.19 ! harris41 447: DBI test application $Revision: 1.18 $
1.9 harris41 448: Using /home/user/DBI-1.14/blib
449: Switch: DBI 1.14 by Tim Bunce, 1.14
450: Available Drivers: ADO, ExampleP, Multiplex, Proxy, mysql
451: dbi:ExampleP:: testing 5 sets of 20 connections:
452: Connecting... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
453: Disconnecting...
454: Connecting... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
455: Disconnecting...
456: Connecting... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
457: Disconnecting...
458: Connecting... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
459: Disconnecting...
460: Connecting... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
461: Disconnecting...
462: Made 100 connections in 0 wallclock secs ( 0.22 usr + 0.03 sys = 0.25 CPU)
463:
464: Testing handle creation speed...
465: 5000 NullP statement handles cycled in 6.6 cpu+sys seconds (762 per sec)
466:
467: test.pl done
468:
469: [root@fenchurch DBI-1.14]# make install
470: These files are installed.
471: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/.packlist
472: /usr/bin/dbiproxy
473: /usr/bin/dbish
474: /usr/lib/perl5/man/man3/Bundle::DBI.3
475: /usr/lib/perl5/man/man3/DBD::ADO.3
476: /usr/lib/perl5/man/man3/DBD::Multiplex.3
477: /usr/lib/perl5/man/man3/DBD::Proxy.3
478: /usr/lib/perl5/man/man3/DBI.3
479: /usr/lib/perl5/man/man3/DBI::DBD.3
480: /usr/lib/perl5/man/man3/DBI::FAQ.3
481: /usr/lib/perl5/man/man3/DBI::Format.3
482: /usr/lib/perl5/man/man3/DBI::ProxyServer.3
483: /usr/lib/perl5/man/man3/DBI::Shell.3
484: /usr/lib/perl5/man/man3/DBI::W32ODBC.3
485: /usr/lib/perl5/man/man3/Win32::DBIODBC.3
486: /usr/lib/perl5/site_perl/5.005/i386-linux/Bundle/DBI.pm
487: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/ADO.pm
488: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/ExampleP.pm
489: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/Multiplex.pm
490: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/NullP.pm
491: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/Proxy.pm
492: /usr/lib/perl5/site_perl/5.005/i386-linux/DBD/Sponge.pm
493: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI.pm
494: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/DBD.pm
495: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/FAQ.pm
496: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/Format.pm
497: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/ProxyServer.pm
498: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/Shell.pm
499: /usr/lib/perl5/site_perl/5.005/i386-linux/DBI/W32ODBC.pm
500: /usr/lib/perl5/site_perl/5.005/i386-linux/Win32/DBIODBC.pm
501: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/DBI.bs
502: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/DBI.so
503: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/DBIXS.h
504: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/Driver.xst
505: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/dbd_xsh.h
506: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/dbi_sql.h
507: /usr/lib/perl5/site_perl/5.005/i386-linux/auto/DBI/dbipport.h
508: /usr/man/man1/dbiproxy.1
509: /usr/man/man1/dbish.1
510: </PRE>
1.8 harris41 511: </P>
512: <FONT COLOR="green"> old notes in green
513: <P>
1.4 harris41 514: The following set of tarballs was found to work together
515: properly on a LON-CAPA RedHat 6.2 system:
516: <UL>
517: <LI>DBI-1.13.tar.gz
518: <LI>Msql-Mysql-modules-1.2209.tar.gz
519: <LI>mysql-3.22.32.tar.gz
520: </UL>
521: </P>
522: <P>
523: Installation was simply a matter of following the instructions
524: and typing the several "make" commands for each
525: </P>
1.8 harris41 526: </FONT>
1.5 harris41 527: <H2>Configuration (automated)</H2>
1.4 harris41 528: <P>
1.17 harris41 529: Not yet stabilized. We are looking at webmin
530: and/or a text-UI tool with less software dependencies
531: than the python-anaconda hunk represented by
532: the prior loncapaconfig.
1.4 harris41 533: </P>
1.5 harris41 534: <H2>Manual configuration</H2>
1.4 harris41 535: <P>
536: This is not complete.
537: </P>
538: <P>
539: <STRONG>Starting the mysql daemon</STRONG>: Login on the Linux
540: system as user 'www'. Enter the command
541: <TT>/usr/local/bin/safe_mysqld &</TT>
542: </P>
543: <P>
544: <STRONG>Set a password for 'root'</STRONG>:
545: <TT>/usr/local/bin/mysqladmin -u root password 'new-password'</TT>
546: </P>
547: <P>
548: <STRONG>Adding a user</STRONG>: Start the mysql daemon. Login to the
549: mysql system as root (<TT>mysql -u root -p mysql</TT>)
550: and enter the right password (for instance 'newmysql'). Add the user
551: www
552: <PRE>
553: INSERT INTO user (Host, User, Password)
554: VALUES ('localhost','www',password('newmysql'));
555: </PRE>
556: </P>
557: <P>
558: <STRONG>Granting privileges to user 'www'</STRONG>:
559: <PRE>
1.19 ! harris41 560: GRANT ALL PRIVILEGES ON loncapa.* TO 'www@localhost';
1.4 harris41 561: FLUSH PRIVILEGES;
562: </PRE>
563: </P>
564: <P>
565: <STRONG>Set the SQL server to start upon system startup</STRONG>:
566: Copy support-files/mysql.server to the right place on the system
567: (/etc/rc.d/...).
568: </P>
1.1 harris41 569: <P>
1.5 harris41 570: <STRONG>The Perl API</STRONG>
1.2 harris41 571: <PRE>
572: $dbh = DBI->connect( "DBI:mysql:loncapa",
573: "www",
574: "SOMEPASSWORD",
575: { RaiseError =>0,PrintError=>0});
576:
577: There is an obvious need to CONNECT to the database, and in order to do
578: this, there must be:
579: a RUNNING mysql daemon;
580: a DATABASE named "loncapa";
581: a USER named "www";
582: and an ABILITY for LON-CAPA on one machine to access
583: SQL database on another machine;
584:
585: So, here are some notes on implementing these configurations.
586:
587: ** RUNNING mysql daemon (safe_mysqld method)
588:
589: The recommended way to run the MySQL daemon is as a non-root user
590: (probably www)...
591:
592: so, 1) login as user www on the linux machine
593: 2) start the mysql daemon as /usr/local/bin/safe_mysqld &
594:
595: safe_mysqld only works if the local installation of MySQL is set to the
596: right directory permissions which I found to be:
597: chown www:users /usr/local/var/mysql
598: chown www:users /usr/local/lib/mysql
599: chown -R www:users /usr/local/mysql
600: chown www:users /usr/local/include/mysql
601: chown www:users /usr/local/var
602:
603: ** DATABASE named "loncapa"
604:
605: As user www, run this command
606: mysql -u root -p mysql
607: enter the password as SOMEPASSWORD
608:
609: This allows you to manually enter MySQL commands.
610: The MySQL command to generate the loncapa DATABASE is:
611:
612: CREATE DATABASE 'loncapa';
613:
614: ** USER named "www"
615:
616: As user www, run this command
617: mysql -u root -p mysql
618: enter the password as SOMEPASSWORD
619:
620: To add the user www to the MySQL server, and grant all
1.18 harris41 621: privileges on loncapa.* to www@localhost identified by 'SOMEPASSWORD'
1.2 harris41 622: with grant option;
623:
624: INSERT INTO user (Host, User, Password)
625: VALUES ('localhost','www',password('SOMEPASSWORD'));
626:
1.19 ! harris41 627: GRANT ALL PRIVILEGES ON loncapa.* TO 'www@localhost';
1.2 harris41 628:
629: FLUSH PRIVILEGES;
630:
631: ** ABILITY for LON-CAPA machines to communicate with SQL databases on
632: other LON-CAPA machines
633:
1.5 harris41 634: An up-to-date lond and lonsql.
635: </PRE>
636: </P>
637: <H2>Testing</H2>
638: <P>
1.11 harris41 639: To test the backend MySQL database, a number of commands should be
640: run after installation.
641: <UL>
642: <LI><TT>cd /usr/local/mysql/sql-bench; ./run-all-tests --small-test</TT></LI>
643: <BR>without the --small-test flag, this test can take more than 10 hours!
644: <LI><TT>cd /usr/local/mysql; bin/mysqladmin version</TT></LI>
645: <LI><TT>cd /usr/local/mysql; bin/mysqladmin variables</TT></LI>
646: <LI><TT>cd /usr/local/mysql; bin/mysqlshow</TT></LI>
647: <LI><TT>cd /usr/local/mysql; bin/mysqlshow mysql</TT></LI>
648: <LI><TT>cd /usr/local/mysql; bin/mysql -e "select host,db,user from db" mysql</TT></LI>
649: <LI><TT>cd /usr/local/mysql/mysql-test; ./test-run-all</TT></LI>
650:
651: </UL>
652: <P>
653: These are sections of perl code which helps test the LON-CAPA network.
1.5 harris41 654: <PRE>
655: <STRONG>** TEST the database connection with my current tester.pl code
656: which mimics what command will eventually be sent through lonc.</STRONG>
1.2 harris41 657:
1.5 harris41 658: $reply=reply(
659: "querysend:SELECT * FROM general_information WHERE Id='AAAAA'",$lonID);
660: </PRE>
661: </P>
662: <H2>Example sections of code relevant to LON-CAPA</H2>
663: <P>
1.2 harris41 664: Here are excerpts of code which implement the above handling:
1.5 harris41 665: </P>
666: <P>
667: <PRE>
668: <STRONG>**LONSQL
1.2 harris41 669: A subroutine from "lonsql" which establishes a child process for handling
1.5 harris41 670: database interactions.</STRONG>
1.2 harris41 671:
672: sub make_new_child {
673: my $pid;
674: my $sigset;
675:
676: # block signal for fork
677: $sigset = POSIX::SigSet->new(SIGINT);
678: sigprocmask(SIG_BLOCK, $sigset)
679: or die "Can't block SIGINT for fork: $!\n";
680:
681: die "fork: $!" unless defined ($pid = fork);
682:
683: if ($pid) {
684: # Parent records the child's birth and returns.
685: sigprocmask(SIG_UNBLOCK, $sigset)
686: or die "Can't unblock SIGINT for fork: $!\n";
687: $children{$pid} = 1;
688: $children++;
689: return;
690: } else {
691: # Child can *not* return from this subroutine.
692: $SIG{INT} = 'DEFAULT'; # make SIGINT kill us as it did before
693:
694: # unblock signals
695: sigprocmask(SIG_UNBLOCK, $sigset)
696: or die "Can't unblock SIGINT for fork: $!\n";
697:
698:
699: #open database handle
700: # making dbh global to avoid garbage collector
701: unless (
702: $dbh = DBI->connect("DBI:mysql:loncapa","www","SOMEPASSWORD",{ RaiseError =>0,PrintError=>0})
703: ) {
704: my $st=120+int(rand(240));
705: &logthis("<font color=blue>WARNING: Couldn't connect to database ($st secs): $@</font>");
706: print "database handle error\n";
707: sleep($st);
708: exit;
709:
710: };
711: # make sure that a database disconnection occurs with ending kill signals
712: $SIG{TERM}=$SIG{INT}=$SIG{QUIT}=$SIG{__DIE__}=\&DISCONNECT;
713:
714: # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
715: for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
716: $client = $server->accept() or last;
717:
718: # do something with the connection
719: $run = $run+1;
720: my $userinput = <$client>;
721: chomp($userinput);
722:
723: my ($conserver,$querytmp)=split(/&/,$userinput);
724: my $query=unescape($querytmp);
725:
726: #send query id which is pid_unixdatetime_runningcounter
727: $queryid = $thisserver;
728: $queryid .="_".($$)."_";
729: $queryid .= time."_";
730: $queryid .= $run;
731: print $client "$queryid\n";
732:
733: #prepare and execute the query
734: my $sth = $dbh->prepare($query);
735: my $result;
736: unless ($sth->execute())
737: {
738: &logthis("<font color=blue>WARNING: Could not retrieve from database: $@</font>");
739: $result="";
740: }
741: else {
742: my $r1=$sth->fetchall_arrayref;
743: my @r2; map {my $a=$_; my @b=map {escape($_)} @$a; push @r2,join(",", @b)} (@$r1);
744: $result=join("&",@r2) . "\n";
745: }
746: &reply("queryreply:$queryid:$result",$conserver);
747:
748: }
749:
750: # tidy up gracefully and finish
751:
752: #close the database handle
753: $dbh->disconnect
754: or &logthis("<font color=blue>WARNING: Couldn't disconnect from database $DBI::errstr ($st secs): $@</font>");
755:
756: # this exit is VERY important, otherwise the child will become
757: # a producer of more and more children, forking yourself into
758: # process death.
759: exit;
760: }
761: }
1.5 harris41 762: </P>
763: <P>
764: <STRONG>** LOND enabling of MySQL requests</STRONG>
765: <BR />
766: This code is part of every lond child process in the
767: way that it parses command request syntax sent to it
768: from lonc processes. Based on the diagram above, querysend
769: corresponds to B-lonc sending the result of the query.
770: queryreply corresponds to B-lond indicating that it has
771: received the request and will start the database transaction
772: (it returns "ok" to
773: A-lonc ($client)).
774: <PRE>
1.2 harris41 775: # ------------------------------------------------------------------- querysend
776: } elsif ($userinput =~ /^querysend/) {
777: my ($cmd,$query)=split(/:/,$userinput);
778: $query=~s/\n*$//g;
779: print $client sqlreply("$hostid{$clientip}\&$query")."\n";
780: # ------------------------------------------------------------------ queryreply
781: } elsif ($userinput =~ /^queryreply/) {
782: my ($cmd,$id,$reply)=split(/:/,$userinput);
783: my $store;
784: my $execdir=$perlvar{'lonDaemons'};
785: if ($store=IO::File->new(">$execdir/tmp/$id")) {
786: print $store $reply;
787: close $store;
788: print $client "ok\n";
789: }
790: else {
791: print $client "error:$!\n";
792: }
793:
1.5 harris41 794: </PRE>
1.2 harris41 795:
1.1 harris41 796: </P>
797: </BODY>
1.3 harris41 798: </HTML>
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