1 collectd - System information collection daemon
2 =================================================
3 http://collectd.org/
5 About
6 -----
8 collectd is a small daemon which collects system information periodically
9 and provides mechanisms to store and monitor the values in a variety of
10 ways.
13 Features
14 --------
16 * collectd is able to collect the following data:
18 - apache
19 Apache server utilization: Number of bytes transfered, number of
20 requests handled and detailed scoreboard statistics
22 - apcups
23 APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.
25 - apple_sensors
26 Sensors in Macs running Mac OS X / Darwin: Temperature, fanspeed and
27 voltage sensors.
29 - ascent
30 Statistics about Ascent, a free server for the game `World of Warcraft'.
32 - battery
33 Batterycharge, -current and voltage of ACPI and PMU based laptop
34 batteries.
36 - bind
37 Name server and resolver statistics from the `statistics-channel'
38 interface of BIND 9.5, 9,6 and later.
40 - cgroups
41 CPU accounting information for process groups under Linux.
43 - conntrack
44 Number of nf_conntrack entries.
46 - contextswitch
47 Number of context switches done by the operating system.
49 - cpu
50 CPU utilization: Time spent in the system, user, nice, idle, and related
51 states.
53 - cpufreq
54 CPU frequency (For laptops with speed step or a similar technology)
56 - curl
57 Parse statistics from websites using regular expressions.
59 - curl_json
60 Retrieves JSON data via cURL and parses it according to user
61 configuration.
63 - curl_xml
64 Retrieves XML data via cURL and parses it according to user
65 configuration.
67 - dbi
68 Executes SQL statements on various databases and interprets the returned
69 data.
71 - df
72 Mountpoint usage (Basically the values `df(1)' delivers)
74 - disk
75 Disk utilization: Sectors read/written, number of read/write actions,
76 average time an IO-operation took to complete.
78 - dns
79 DNS traffic: Query types, response codes, opcodes and traffic/octets
80 transfered.
82 - email
83 Email statistics: Count, traffic, spam scores and checks.
84 See collectd-email(5).
86 - entropy
87 Amount of entropy available to the system.
89 - ethstat
90 Network interface card statistics.
92 - exec
93 Values gathered by a custom program or script.
94 See collectd-exec(5).
96 - filecount
97 Count the number of files in directories.
99 - fscache
100 Linux file-system based caching framework statistics.
102 - gmond
103 Receive multicast traffic from Ganglia instances.
105 - hddtemp
106 Harddisk temperatures using hddtempd.
108 - interface
109 Interface traffic: Number of octets, packets and errors for each
110 interface.
112 - iptables
113 Iptables' counters: Number of bytes that were matched by a certain
114 iptables rule.
116 - ipmi
117 IPMI (Intelligent Platform Management Interface) sensors information.
119 - ipvs
120 IPVS connection statistics (number of connections, octets and packets
121 for each service and destination).
122 See http://www.linuxvirtualserver.org/software/index.html.
124 - irq
125 IRQ counters: Frequency in which certain interrupts occur.
127 - java
128 Integrates a `Java Virtual Machine' (JVM) to execute plugins in Java
129 bytecode. See “Configuring with libjvm” below.
131 - load
132 System load average over the last 1, 5 and 15 minutes.
134 - lpar
135 Detailed CPU statistics of the “Logical Partitions” virtualization
136 technique built into IBM's POWER processors.
138 - libvirt
139 CPU, memory, disk and network I/O statistics from virtual machines.
141 - lvm
142 Size of “Logical Volumes” (LV) and “Volume Groups” (VG) of Linux'
143 “Logical Volume Manager” (LVM).
145 - madwifi
146 Queries very detailed usage statistics from wireless LAN adapters and
147 interfaces that use the Atheros chipset and the MadWifi driver.
149 - mbmon
150 Motherboard sensors: temperature, fanspeed and voltage information,
151 using mbmon(1).
153 - md
154 Linux software-RAID device information (number of active, failed, spare
155 and missing disks).
157 - memcachec
158 Query and parse data from a memcache daemon (memcached).
160 - memcached
161 Statistics of the memcached distributed caching system.
162 <http://www.danga.com/memcached/>
164 - memory
165 Memory utilization: Memory occupied by running processes, page cache,
166 buffer cache and free.
168 - mic
169 Collects CPU usage, memory usage, temperatures and power consumption from
170 Intel Many Integrated Core (MIC) CPUs.
172 - modbus
173 Reads values from Modbus/TCP enabled devices. Supports reading values
174 from multiple "slaves" so gateway devices can be used.
176 - multimeter
177 Information provided by serial multimeters, such as the `Metex
178 M-4650CR'.
180 - mysql
181 MySQL server statistics: Commands issued, handlers triggered, thread
182 usage, query cache utilization and traffic/octets sent and received.
184 - netapp
185 Plugin to query performance values from a NetApp storage system using the
186 “Manage ONTAP” SDK provided by NetApp.
188 - netlink
189 Very detailed Linux network interface and routing statistics. You can get
190 (detailed) information on interfaces, qdiscs, classes, and, if you can
191 make use of it, filters.
193 - network
194 Receive values that were collected by other hosts. Large setups will
195 want to collect the data on one dedicated machine, and this is the
196 plugin of choice for that.
198 - nfs
199 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
200 NFSv3 right now.
202 - nginx
203 Collects statistics from `nginx' (speak: engine X), a HTTP and mail
204 server/proxy.
206 - ntpd
207 NTP daemon statistics: Local clock drift, offset to peers, etc.
209 - nut
210 Network UPS tools: UPS current, voltage, power, charge, utilisation,
211 temperature, etc. See upsd(8).
213 - numa
214 Information about Non-Uniform Memory Access (NUMA).
216 - olsrd
217 Queries routing information from the “Optimized Link State Routing”
218 daemon.
220 - onewire (EXPERIMENTAL!)
221 Read onewire sensors using the owcapu library of the owfs project.
222 Please read in collectd.conf(5) why this plugin is experimental.
224 - openvpn
225 RX and TX of each client in openvpn-status.log (status-version 2).
226 <http://openvpn.net/index.php/documentation/howto.html>
228 - oracle
229 Query data from an Oracle database.
231 - perl
232 The perl plugin implements a Perl-interpreter into collectd. You can
233 write your own plugins in Perl and return arbitrary values using this
234 API. See collectd-perl(5).
236 - pf
237 Query statistics from BSD's packet filter "pf".
239 - pinba
240 Receive and dispatch timing values from Pinba, a profiling extension for
241 PHP.
243 - ping
244 Network latency: Time to reach the default gateway or another given
245 host.
247 - postgresql
248 PostgreSQL database statistics: active server connections, transaction
249 numbers, block IO, table row manipulations.
251 - powerdns
252 PowerDNS name server statistics.
254 - processes
255 Process counts: Number of running, sleeping, zombie, ... processes.
257 - protocols
258 Counts various aspects of network protocols such as IP, TCP, UDP, etc.
260 - python
261 The python plugin implements a Python interpreter into collectd. This
262 makes it possible to write plugins in Python which are executed by
263 collectd without the need to start a heavy interpreter every interval.
264 See collectd-python(5) for details.
266 - redis
267 The redis plugin gathers information from a redis server, including:
268 uptime, used memory, total connections etc.
270 - routeros
271 Query interface and wireless registration statistics from RouterOS.
273 - rrdcached
274 RRDtool caching daemon (RRDcacheD) statistics.
276 - sensors
277 System sensors, accessed using lm_sensors: Voltages, temperatures and
278 fan rotation speeds.
280 - serial
281 RX and TX of serial interfaces. Linux only; needs root privileges.
283 - snmp
284 Read values from SNMP (Simple Network Management Protocol) enabled
285 network devices such as switches, routers, thermometers, rack monitoring
286 servers, etc. See collectd-snmp(5).
288 - swap
289 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
291 - table
292 Parse table-like structured files.
294 - tail
295 Follows (tails) logfiles, parses them by lines and submits matched
296 values.
298 - tail_csv
299 Follows (tails) files in CSV format, parses each line and submits
300 extracted values.
302 - tape
303 Bytes and operations read and written on tape devices. Solaris only.
305 - tcpconns
306 Number of TCP connections to specific local and remote ports.
308 - teamspeak2
309 TeamSpeak2 server statistics.
311 - ted
312 Plugin to read values from `The Energy Detective' (TED).
314 - thermal
315 Linux ACPI thermal zone information.
317 - tokyotyrant
318 Reads the number of records and file size from a running Tokyo Tyrant
319 server.
321 - uptime
322 System uptime statistics.
324 - users
325 Users currently logged in.
327 - varnish
328 Various statistics from Varnish, an HTTP accelerator.
330 - vmem
331 Virtual memory statistics, e. g. the number of page-ins/-outs or the
332 number of pagefaults.
334 - vserver
335 System resources used by Linux VServers.
336 See <http://linux-vserver.org/>.
338 - wireless
339 Link quality of wireless cards. Linux only.
341 - xmms
342 Bitrate and frequency of music played with XMMS.
344 - zfs_arc
345 Statistics for ZFS' “Adaptive Replacement Cache” (ARC).
347 * Output can be written or sent to various destinations by the following
348 plugins:
350 - amqp
351 Sends JSON-encoded data to an Advanced Message Queuing Protocol (AMQP)
352 server, such as RabbitMQ.
354 - csv
355 Write to comma separated values (CSV) files. This needs lots of
356 diskspace but is extremely portable and can be analysed with almost
357 every program that can analyse anything. Even Microsoft's Excel..
359 - network
360 Send the data to a remote host to save the data somehow. This is useful
361 for large setups where the data should be saved by a dedicated machine.
363 - perl
364 Of course the values are propagated to plugins written in Perl, too, so
365 you can easily do weird stuff with the plugins we didn't dare think of
366 ;) See collectd-perl(5).
368 - python
369 It's possible to implement write plugins in Python using the python
370 plugin. See collectd-python(5) for details.
372 - rrdcached
373 Output to round-robin-database (RRD) files using the RRDtool caching
374 daemon (RRDcacheD) - see rrdcached(1). That daemon provides a general
375 implementation of the caching done by the `rrdtool' plugin.
377 - rrdtool
378 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
379 This is likely the most popular destination for such values. Since
380 updates to RRD-files are somewhat expensive this plugin can cache
381 updates to the files and write a bunch of updates at once, which lessens
382 system load a lot.
384 - unixsock
385 One can query the values from the unixsock plugin whenever they're
386 needed. Please read collectd-unixsock(5) for a description on how that's
387 done.
389 - write_graphite
390 Sends data to Carbon, the storage layer of Graphite using TCP or UDP. It
391 can be configured to avoid logging send errors (especially useful when
392 using UDP).
394 - write_http
395 Sends the values collected by collectd to a web-server using HTTP POST
396 requests. The transmitted data is either in a form understood by the
397 Exec plugin or formatted in JSON.
399 - write_mongodb
400 Sends data to MongoDB, a NoSQL database.
402 - write_redis
403 Sends the values to a Redis key-value database server.
405 - write_riemann
406 Sends data to Riemann, a stream processing and monitoring system.
408 * Logging is, as everything in collectd, provided by plugins. The following
409 plugins keep up informed about what's going on:
411 - logfile
412 Writes logmessages to a file or STDOUT/STDERR.
414 - perl
415 Log messages are propagated to plugins written in Perl as well.
416 See collectd-perl(5).
418 - python
419 It's possible to implement log plugins in Python using the python plugin.
420 See collectd-python(5) for details.
422 - syslog
423 Logs to the standard UNIX logging mechanism, syslog.
425 * Notifications can be handled by the following plugins:
427 - notify_desktop
428 Send a desktop notification to a notification daemon, as defined in
429 the Desktop Notification Specification. To actually display the
430 notifications, notification-daemon is required.
431 See http://www.galago-project.org/specs/notification/.
433 - notify_email
434 Send an E-mail with the notification message to the configured
435 recipients.
437 - exec
438 Execute a program or script to handle the notification.
439 See collectd-exec(5).
441 - logfile
442 Writes the notification message to a file or STDOUT/STDERR.
444 - network
445 Send the notification to a remote host to handle it somehow.
447 - perl
448 Notifications are propagated to plugins written in Perl as well.
449 See collectd-perl(5).
451 - python
452 It's possible to implement notification plugins in Python using the
453 python plugin. See collectd-python(5) for details.
455 * Value processing can be controlled using the "filter chain" infrastructure
456 and "matches" and "targets". The following plugins are available:
458 - match_empty_counter
459 Match counter values which are currently zero.
461 - match_hashed
462 Match values using a hash function of the hostname.
464 - match_regex
465 Match values by their identifier based on regular expressions.
467 - match_timediff
468 Match values with an invalid timestamp.
470 - match_value
471 Select values by their data sources' values.
473 - target_notification
474 Create and dispatch a notification.
476 - target_replace
477 Replace parts of an identifier using regular expressions.
479 - target_scale
480 Scale (multiply) values by an arbitrary value.
482 - target_set
483 Set (overwrite) entire parts of an identifier.
485 * Miscellaneous plugins:
487 - aggregation
488 Selects multiple value lists based on patterns or regular expressions
489 and creates new aggregated values lists from those.
491 - threshold
492 Checks values against configured thresholds and creates notifications if
493 values are out of bounds. See collectd-threshold(5) for details.
495 - uuid
496 Sets the hostname to an unique identifier. This is meant for setups
497 where each client may migrate to another physical host, possibly going
498 through one or more name changes in the process.
500 * Performance: Since collectd is running as a daemon it doesn't spend much
501 time starting up again and again. With the exception of the exec plugin no
502 processes are forked. Caching in output plugins, such as the rrdtool and
503 network plugins, makes sure your resources are used efficiently. Also,
504 since collectd is programmed multithreaded it benefits from hyperthreading
505 and multicore processors and makes sure that the daemon isn't idle if only
506 one plugin waits for an IO-operation to complete.
508 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
509 as possible and the default values should be okay for most users.
512 Operation
513 ---------
515 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
516 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
517 for a list of options and a syntax description.
519 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
520 files. The usual place for these files is beneath `/var/lib/collectd'.
522 * When using some of the plugins, collectd needs to run as user root, since
523 only root can do certain things, such as craft ICMP packages needed to ping
524 other hosts. collectd should NOT be installed setuid root since it can be
525 used to overwrite valuable files!
527 * Sample scripts to generate graphs reside in `contrib/' in the source
528 package or somewhere near `/usr/share/doc/collectd' in most distributions.
529 Please be aware that those script are meant as a starting point for your
530 own experiments.. Some of them require the `RRDs' Perl module.
531 (`librrds-perl' on Debian) If you have written a more sophisticated
532 solution please share it with us.
534 * The RRAs of the automatically created RRD files depend on the `step'
535 and `heartbeat' settings given. If change these settings you may need to
536 re-create the files, losing all data. Please be aware of that when changing
537 the values and read the rrdtool(1) manpage thoroughly.
540 collectd and chkrootkit
541 -----------------------
543 If you are using the `dns' plugin chkrootkit(1) will report collectd as a
544 packet sniffer ("<iface>: PACKET SNIFFER(/usr/sbin/collectd[<pid>])"). The
545 plugin captures all UDP packets on port 53 to analyze the DNS traffic. In
546 this case, collectd is a legitimate sniffer and the report should be
547 considered to be a false positive. However, you might want to check that
548 this really is collectd and not some other, illegitimate sniffer.
551 Prerequisites
552 -------------
554 To compile collectd from source you will need:
556 * Usual suspects: C compiler, linker, preprocessor, make, ...
558 * A POSIX-threads (pthread) implementation.
559 Since gathering some statistics is slow (network connections, slow devices,
560 etc) the collectd is parallelized. The POSIX threads interface is being
561 used and should be found in various implementations for hopefully all
562 platforms.
564 * CoreFoundation.framework and IOKit.framework (optional)
565 For compiling on Darwin in general and the `apple_sensors' plugin in
566 particular.
567 <http://developer.apple.com/corefoundation/>
569 * libclntsh (optional)
570 Used by the `oracle' plugin.
572 * libcredis (optional)
573 Used by the redis plugin. Please note that you require a 0.2.2 version
574 or higher. <http://code.google.com/p/credis/>
576 * libcurl (optional)
577 If you want to use the `apache', `ascent', `curl', `nginx', or `write_http'
578 plugin.
579 <http://curl.haxx.se/>
581 * libdbi (optional)
582 Used by the `dbi' plugin to connect to various databases.
583 <http://libdbi.sourceforge.net/>
585 * libesmtp (optional)
586 For the `notify_email' plugin.
587 <http://www.stafford.uklinux.net/libesmtp/>
589 * libganglia (optional)
590 Used by the `gmond' plugin to process data received from Ganglia.
591 <http://ganglia.info/>
593 * libgcrypt (optional)
594 Used by the `network' plugin for encryption and authentication.
595 <http://www.gnupg.org/>
597 * libhal (optional)
598 If present, the uuid plugin will check for UUID from HAL.
599 <http://hal.freedesktop.org/>
601 * libiptc (optional)
602 For querying iptables counters.
603 <http://netfilter.org/>
605 If not found on the system, a version shipped with this distribution can
606 be used. It requires some Linux headers in /usr/include/linux. You can
607 force the build system to use the shipped version by specifying
608 --with-libiptc=shipped
609 when running the configure script.
611 * libjvm (optional)
612 Library that encapsulates the `Java Virtual Machine' (JVM). This library is
613 used by the Java plugin to execute Java bytecode. See “Configuring with
614 libjvm” below.
615 <http://openjdk.java.net/> (and others)
617 * libmemcached (optional)
618 Used by the `memcachec' plugin to connect to a memcache daemon.
619 <http://tangent.org/552/libmemcached.html>
621 * libmodbus (optional)
622 Used by the “modbus” plugin to communicate with Modbus/TCP devices. The
623 “modbus” plugin works with version 2.0.3 of the library – due to frequent
624 API changes other versions may or may not compile cleanly.
625 <http://www.libmodbus.org/>
627 * libmysqlclient (optional)
628 Unsurprisingly used by the `mysql' plugin.
629 <http://dev.mysql.com/>
631 * libnetapp (optional)
632 Required for the “netapp” plugin.
633 This library is part of the “Manage ONTAP SDK” published by NetApp.
635 * libnetlink (optional)
636 Used, obviously, for the `netlink' plugin.
637 <http://www.linuxfoundation.org/en/Net:Iproute2>
639 * libnetsnmp (optional)
640 For the `snmp' plugin.
641 <http://www.net-snmp.org/>
643 * libnotify (optional)
644 For the `notify_desktop' plugin.
645 <http://www.galago-project.org/>
647 * liboping (optional)
648 Used by the `ping' plugin to send and receive ICMP packets.
649 <http://verplant.org/liboping/>
651 * libowcapi (optional)
652 Used by the `onewire' plugin to read values from onewire sensors (or the
653 owserver(1) daemon).
654 <http://www.owfs.org/>
656 * libpcap (optional)
657 Used to capture packets by the `dns' plugin.
658 <http://www.tcpdump.org/>
660 * libperfstat (optional)
661 Used by various plugins to gather statistics under AIX.
663 * libperl (optional)
664 Obviously used by the `perl' plugin. The library has to be compiled with
665 ithread support (introduced in Perl 5.6.0).
666 <http://www.perl.org/>
668 * libpq (optional)
669 The PostgreSQL C client library used by the `postgresql' plugin.
670 <http://www.postgresql.org/>
672 * libprotobuf-c, protoc-c (optional)
673 Used by the `pinba' plugin to generate a parser for the network packets
674 sent by the Pinba PHP extension.
675 <http://code.google.com/p/protobuf-c/>
677 * libpython (optional)
678 Used by the `python' plugin. Currently, Python 2.3 and later and Python 3
679 are supported.
680 <http://www.python.org/>
682 * librabbitmq (optional; also called “rabbitmq-c”)
683 Used by the AMQP plugin for AMQP connections, for example to RabbitMQ.
684 <http://hg.rabbitmq.com/rabbitmq-c/>
686 * librouteros (optional)
687 Used by the `routeros' plugin to connect to a device running `RouterOS'.
688 <http://verplant.org/librouteros/>
690 * librrd (optional)
691 Used by the `rrdtool' and `rrdcached' plugins. The latter requires RRDtool
692 client support which was added after version 1.3 of RRDtool. Versions 1.0,
693 1.2 and 1.3 are known to work with the `rrdtool' plugin.
694 <http://oss.oetiker.ch/rrdtool/>
696 * librt, libsocket, libkstat, libdevinfo (optional)
697 Various standard Solaris libraries which provide system functions.
698 <http://developers.sun.com/solaris/>
700 * libsensors (optional)
701 To read from `lm_sensors', see the `sensors' plugin.
702 <http://www.lm-sensors.org/>
704 * libstatgrab (optional)
705 Used by various plugins to collect statistics on systems other than Linux
706 and/or Solaris.
707 <http://www.i-scream.org/libstatgrab/>
709 * libtokyotyrant (optional)
710 Used by the tokyotyrant plugin.
711 <http://1978th.net/tokyotyrant/>
713 * libupsclient/nut (optional)
714 For the `nut' plugin which queries nut's `upsd'.
715 <http://networkupstools.org/>
717 * libvirt (optional)
718 Collect statistics from virtual machines.
719 <http://libvirt.org/>
721 * libxml2 (optional)
722 Parse XML data. This is needed for the `ascent' and `libvirt' plugins.
723 <http://xmlsoft.org/>
725 * libxmms (optional)
726 <http://www.xmms.org/>
728 * libyajl (optional)
729 Parse JSON data. This is needed for the `curl_json' plugin.
730 <http://github.com/lloyd/yajl>
732 * libvarnish (optional)
733 Fetches statistics from a Varnish instance. This is needed for the Varnish plugin
734 <http://varnish-cache.org>
736 Configuring / Compiling / Installing
737 ------------------------------------
739 To configure, build and install collectd with the default settings, run
740 `./configure && make && make install'. For detailed, generic instructions
741 see INSTALL. For a complete list of configure options and their description,
742 run `./configure --help'.
744 By default, the configure script will check for all build dependencies and
745 disable all plugins whose requirements cannot be fulfilled (any other plugin
746 will be enabled). To enable a plugin, install missing dependencies (see
747 section `Prerequisites' above) and rerun `configure'. If you specify the
748 `--enable-<plugin>' configure option, the script will fail if the depen-
749 dencies for the specified plugin are not met. In that case you can force the
750 plugin to be built using the `--enable-<plugin>=force' configure option.
751 This will most likely fail though unless you're working in a very unusual
752 setup and you really know what you're doing. If you specify the
753 `--disable-<plugin>' configure option, the plugin will not be built. If you
754 specify the `--enable-all-plugins' or `--disable-all-plugins' configure
755 options, all plugins will be enabled or disabled respectively by default.
756 Explicitly enabling or disabling a plugin overwrites the default for the
757 specified plugin. These options are meant for package maintainers and should
758 not be used in everyday situations.
760 By default, collectd will be installed into `/opt/collectd'. You can adjust
761 this setting by specifying the `--prefix' configure option - see INSTALL for
762 details. If you pass DESTDIR=<path> to `make install', <path> will be
763 prefixed to all installation directories. This might be useful when creating
764 packages for collectd.
766 Configuring with libjvm
767 -----------------------
769 To determine the location of the required files of a Java installation is not
770 an easy task, because the locations vary with your kernel (Linux, SunOS, …)
771 and with your architecture (x86, SPARC, …) and there is no ‘java-config’
772 script we could use. Configuration of the JVM library is therefore a bit
773 tricky.
775 The easiest way to use the `--with-java=$JAVA_HOME' option, where
776 `$JAVA_HOME' is usually something like:
777 /usr/lib/jvm/java-1.5.0-sun-1.5.0.14
779 The configure script will then use find(1) to look for the following files:
781 - jni.h
782 - jni_md.h
783 - libjvm.so
785 If found, appropriate CPP-flags and LD-flags are set and the following
786 library checks succeed.
788 If this doesn't work for you, you have the possibility to specify CPP-flags,
789 C-flags and LD-flags for the ‘Java’ plugin by hand, using the following three
790 (environment) variables:
792 - JAVA_CPPFLAGS
793 - JAVA_CFLAGS
794 - JAVA_LDFLAGS
796 For example (shortened for demonstration purposes):
798 ./configure JAVA_CPPFLAGS="-I$JAVA_HOME/include -I$JAVA_HOME/include/linux"
800 Adding "-ljvm" to the JAVA_LDFLAGS is done automatically, you don't have to
801 do that.
803 Crosscompiling
804 --------------
806 To compile correctly collectd needs to be able to initialize static
807 variables to NAN (Not A Number). Some C libraries, especially the GNU
808 libc, have a problem with that.
810 Luckily, with GCC it's possible to work around that problem: One can define
811 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
812 ``implementation'' the configure script needs to compile and run a short
813 test program. Obviously running a test program when doing a cross-
814 compilation is, well, challenging.
816 If you run into this problem, you can use the `--with-nan-emulation'
817 configure option to force the use of this implementation. We can't promise
818 that the compiled binary actually behaves as it should, but since NANs
819 are likely never passed to the libm you have a good chance to be lucky.
821 Likewise, collectd needs to know the layout of doubles in memory, in order
822 to craft uniform network packets over different architectures. For this, it
823 needs to know how to convert doubles into the memory layout used by x86. The
824 configure script tries to figure this out by compiling and running a few
825 small test programs. This is of course not possible when cross-compiling.
826 You can use the `--with-fp-layout' option to tell the configure script which
827 conversion method to assume. Valid arguments are:
829 * `nothing' (12345678 -> 12345678)
830 * `endianflip' (12345678 -> 87654321)
831 * `intswap' (12345678 -> 56781234)
834 Contact
835 -------
837 For questions, bug reports, development information and basically all other
838 concerns please send an email to collectd's mailing list at
839 <collectd at verplant.org>.
841 For live discussion and more personal contact visit us in IRC, we're in
842 channel #collectd on freenode.
845 Author
846 ------
848 Florian octo Forster <octo at verplant.org>,
849 Sebastian tokkee Harl <sh at tokkee.org>,
850 and many contributors (see `AUTHORS').
852 Please send bug reports and patches to the mailing list, see `Contact'
853 above.