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 - conntrack
41 Number of nf_conntrack entries.
43 - contextswitch
44 Number of context switches done by the operating system.
46 - cpu
47 CPU utilization: Time spent in the system, user, nice, idle, and related
48 states.
50 - cpufreq
51 CPU frequency (For laptops with speed step or a similar technology)
53 - curl
54 Parse statistics from websites using regular expressions.
56 - curl_json
57 Retrieves JSON data via cURL and parses it according to user
58 configuration.
60 - curl_xml
61 Retrieves XML data via cURL and parses it according to user
62 configuration.
64 - dbi
65 Executes SQL statements on various databases and interprets the returned
66 data.
68 - df
69 Mountpoint usage (Basically the values `df(1)' delivers)
71 - disk
72 Disk utilization: Sectors read/written, number of read/write actions,
73 average time an IO-operation took to complete.
75 - dns
76 DNS traffic: Query types, response codes, opcodes and traffic/octets
77 transfered.
79 - email
80 Email statistics: Count, traffic, spam scores and checks.
81 See collectd-email(5).
83 - entropy
84 Amount of entropy available to the system.
86 - ethstat
87 Network interface card statistics.
89 - exec
90 Values gathered by a custom program or script.
91 See collectd-exec(5).
93 - filecount
94 Count the number of files in directories.
96 - fscache
97 Linux file-system based caching framework statistics.
99 - gmond
100 Receive multicast traffic from Ganglia instances.
102 - hddtemp
103 Harddisk temperatures using hddtempd.
105 - interface
106 Interface traffic: Number of octets, packets and errors for each
107 interface.
109 - iptables
110 Iptables' counters: Number of bytes that were matched by a certain
111 iptables rule.
113 - ipmi
114 IPMI (Intelligent Platform Management Interface) sensors information.
116 - ipvs
117 IPVS connection statistics (number of connections, octets and packets
118 for each service and destination).
119 See http://www.linuxvirtualserver.org/software/index.html.
121 - irq
122 IRQ counters: Frequency in which certain interrupts occur.
124 - java
125 Integrates a `Java Virtual Machine' (JVM) to execute plugins in Java
126 bytecode. See “Configuring with libjvm” below.
128 - load
129 System load average over the last 1, 5 and 15 minutes.
131 - lpar
132 Detailed CPU statistics of the “Logical Partitions” virtualization
133 technique built into IBM's POWER processors.
135 - libvirt
136 CPU, memory, disk and network I/O statistics from virtual machines.
138 - madwifi
139 Queries very detailed usage statistics from wireless LAN adapters and
140 interfaces that use the Atheros chipset and the MadWifi driver.
142 - mbmon
143 Motherboard sensors: temperature, fanspeed and voltage information,
144 using mbmon(1).
146 - md
147 Linux software-RAID device information (number of active, failed, spare
148 and missing disks).
150 - memcachec
151 Query and parse data from a memcache daemon (memcached).
153 - memcached
154 Statistics of the memcached distributed caching system.
155 <http://www.danga.com/memcached/>
157 - memory
158 Memory utilization: Memory occupied by running processes, page cache,
159 buffer cache and free.
161 - modbus
162 Reads values from Modbus/TCP enabled devices. Supports reading values
163 from multiple "slaves" so gateway devices can be used.
165 - multimeter
166 Information provided by serial multimeters, such as the `Metex
167 M-4650CR'.
169 - mysql
170 MySQL server statistics: Commands issued, handlers triggered, thread
171 usage, query cache utilization and traffic/octets sent and received.
173 - netapp
174 Plugin to query performance values from a NetApp storage system using the
175 “Manage ONTAP” SDK provided by NetApp.
177 - netlink
178 Very detailed Linux network interface and routing statistics. You can get
179 (detailed) information on interfaces, qdiscs, classes, and, if you can
180 make use of it, filters.
182 - network
183 Receive values that were collected by other hosts. Large setups will
184 want to collect the data on one dedicated machine, and this is the
185 plugin of choice for that.
187 - nfs
188 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
189 NFSv3 right now.
191 - nginx
192 Collects statistics from `nginx' (speak: engine X), a HTTP and mail
193 server/proxy.
195 - ntpd
196 NTP daemon statistics: Local clock drift, offset to peers, etc.
198 - nut
199 Network UPS tools: UPS current, voltage, power, charge, utilisation,
200 temperature, etc. See upsd(8).
202 - numa
203 Information about Non-Uniform Memory Access (NUMA).
205 - olsrd
206 Queries routing information from the “Optimized Link State Routing”
207 daemon.
209 - onewire (EXPERIMENTAL!)
210 Read onewire sensors using the owcapu library of the owfs project.
211 Please read in collectd.conf(5) why this plugin is experimental.
213 - openvpn
214 RX and TX of each client in openvpn-status.log (status-version 2).
215 <http://openvpn.net/index.php/documentation/howto.html>
217 - oracle
218 Query data from an Oracle database.
220 - perl
221 The perl plugin implements a Perl-interpreter into collectd. You can
222 write your own plugins in Perl and return arbitrary values using this
223 API. See collectd-perl(5).
225 - pf
226 Query statistics from BSD's packet filter "pf".
228 - pinba
229 Receive and dispatch timing values from Pinba, a profiling extension for
230 PHP.
232 - ping
233 Network latency: Time to reach the default gateway or another given
234 host.
236 - postgresql
237 PostgreSQL database statistics: active server connections, transaction
238 numbers, block IO, table row manipulations.
240 - powerdns
241 PowerDNS name server statistics.
243 - processes
244 Process counts: Number of running, sleeping, zombie, ... processes.
246 - protocols
247 Counts various aspects of network protocols such as IP, TCP, UDP, etc.
249 - python
250 The python plugin implements a Python interpreter into collectd. This
251 makes it possible to write plugins in Python which are executed by
252 collectd without the need to start a heavy interpreter every interval.
253 See collectd-python(5) for details.
255 - redis
256 The redis plugin gathers information from a redis server, including:
257 uptime, used memory, total connections etc.
259 - routeros
260 Query interface and wireless registration statistics from RouterOS.
262 - rrdcached
263 RRDtool caching daemon (RRDcacheD) statistics.
265 - sensors
266 System sensors, accessed using lm_sensors: Voltages, temperatures and
267 fan rotation speeds.
269 - serial
270 RX and TX of serial interfaces. Linux only; needs root privileges.
272 - snmp
273 Read values from SNMP (Simple Network Management Protocol) enabled
274 network devices such as switches, routers, thermometers, rack monitoring
275 servers, etc. See collectd-snmp(5).
277 - swap
278 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
280 - table
281 Parse table-like structured files.
283 - tail
284 Follows (tails) logfiles, parses them by lines and submits matched
285 values.
287 - tail_csv
288 Follows (tails) files in CSV format, parses each line and submits
289 extracted values.
291 - tape
292 Bytes and operations read and written on tape devices. Solaris only.
294 - tcpconns
295 Number of TCP connections to specific local and remote ports.
297 - teamspeak2
298 TeamSpeak2 server statistics.
300 - ted
301 Plugin to read values from `The Energy Detective' (TED).
303 - thermal
304 Linux ACPI thermal zone information.
306 - tokyotyrant
307 Reads the number of records and file size from a running Tokyo Tyrant
308 server.
310 - uptime
311 System uptime statistics.
313 - users
314 Users currently logged in.
316 - varnish
317 Various statistics from Varnish, an HTTP accelerator.
319 - vmem
320 Virtual memory statistics, e. g. the number of page-ins/-outs or the
321 number of pagefaults.
323 - vserver
324 System resources used by Linux VServers.
325 See <http://linux-vserver.org/>.
327 - wireless
328 Link quality of wireless cards. Linux only.
330 - xmms
331 Bitrate and frequency of music played with XMMS.
333 - zfs_arc
334 Statistics for ZFS' “Adaptive Replacement Cache” (ARC).
336 * Output can be written or sent to various destinations by the following
337 plugins:
339 - amqp
340 Sends JSON-encoded data to an Advanced Message Queuing Protocol (AMQP)
341 server, such as RabbitMQ.
343 - csv
344 Write to comma separated values (CSV) files. This needs lots of
345 diskspace but is extremely portable and can be analysed with almost
346 every program that can analyse anything. Even Microsoft's Excel..
348 - network
349 Send the data to a remote host to save the data somehow. This is useful
350 for large setups where the data should be saved by a dedicated machine.
352 - perl
353 Of course the values are propagated to plugins written in Perl, too, so
354 you can easily do weird stuff with the plugins we didn't dare think of
355 ;) See collectd-perl(5).
357 - python
358 It's possible to implement write plugins in Python using the python
359 plugin. See collectd-python(5) for details.
361 - rrdcached
362 Output to round-robin-database (RRD) files using the RRDtool caching
363 daemon (RRDcacheD) - see rrdcached(1). That daemon provides a general
364 implementation of the caching done by the `rrdtool' plugin.
366 - rrdtool
367 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
368 This is likely the most popular destination for such values. Since
369 updates to RRD-files are somewhat expensive this plugin can cache
370 updates to the files and write a bunch of updates at once, which lessens
371 system load a lot.
373 - unixsock
374 One can query the values from the unixsock plugin whenever they're
375 needed. Please read collectd-unixsock(5) for a description on how that's
376 done.
378 - write_graphite
379 Sends data to Carbon, the storage layer of Graphite.
381 - write_http
382 Sends the values collected by collectd to a web-server using HTTP POST
383 requests. The transmitted data is either in a form understood by the
384 Exec plugin or formatted in JSON.
386 - write_mongodb
387 Sends data to MongoDB, a NoSQL database.
389 - write_redis
390 Sends the values to a Redis key-value database server.
392 - write_riemann
393 Sends data to Riemann, a stream processing and monitoring system.
395 * Logging is, as everything in collectd, provided by plugins. The following
396 plugins keep up informed about what's going on:
398 - logfile
399 Writes logmessages to a file or STDOUT/STDERR.
401 - perl
402 Log messages are propagated to plugins written in Perl as well.
403 See collectd-perl(5).
405 - python
406 It's possible to implement log plugins in Python using the python plugin.
407 See collectd-python(5) for details.
409 - syslog
410 Logs to the standard UNIX logging mechanism, syslog.
412 * Notifications can be handled by the following plugins:
414 - notify_desktop
415 Send a desktop notification to a notification daemon, as defined in
416 the Desktop Notification Specification. To actually display the
417 notifications, notification-daemon is required.
418 See http://www.galago-project.org/specs/notification/.
420 - notify_email
421 Send an E-mail with the notification message to the configured
422 recipients.
424 - exec
425 Execute a program or script to handle the notification.
426 See collectd-exec(5).
428 - logfile
429 Writes the notification message to a file or STDOUT/STDERR.
431 - network
432 Send the notification to a remote host to handle it somehow.
434 - perl
435 Notifications are propagated to plugins written in Perl as well.
436 See collectd-perl(5).
438 - python
439 It's possible to implement notification plugins in Python using the
440 python plugin. See collectd-python(5) for details.
442 * Value processing can be controlled using the "filter chain" infrastructure
443 and "matches" and "targets". The following plugins are available:
445 - match_empty_counter
446 Match counter values which are currently zero.
448 - match_hashed
449 Match values using a hash function of the hostname.
451 - match_regex
452 Match values by their identifier based on regular expressions.
454 - match_timediff
455 Match values with an invalid timestamp.
457 - match_value
458 Select values by their data sources' values.
460 - target_notification
461 Create and dispatch a notification.
463 - target_replace
464 Replace parts of an identifier using regular expressions.
466 - target_scale
467 Scale (multiply) values by an arbitrary value.
469 - target_set
470 Set (overwrite) entire parts of an identifier.
472 * Miscellaneous plugins:
474 - aggregation
475 Selects multiple value lists based on patterns or regular expressions
476 and creates new aggregated values lists from those.
478 - threshold
479 Checks values against configured thresholds and creates notifications if
480 values are out of bounds. See collectd-threshold(5) for details.
482 - uuid
483 Sets the hostname to an unique identifier. This is meant for setups
484 where each client may migrate to another physical host, possibly going
485 through one or more name changes in the process.
487 * Performance: Since collectd is running as a daemon it doesn't spend much
488 time starting up again and again. With the exception of the exec plugin no
489 processes are forked. Caching in output plugins, such as the rrdtool and
490 network plugins, makes sure your resources are used efficiently. Also,
491 since collectd is programmed multithreaded it benefits from hyperthreading
492 and multicore processors and makes sure that the daemon isn't idle if only
493 one plugin waits for an IO-operation to complete.
495 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
496 as possible and the default values should be okay for most users.
499 Operation
500 ---------
502 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
503 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
504 for a list of options and a syntax description.
506 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
507 files. The usual place for these files is beneath `/var/lib/collectd'.
509 * When using some of the plugins, collectd needs to run as user root, since
510 only root can do certain things, such as craft ICMP packages needed to ping
511 other hosts. collectd should NOT be installed setuid root since it can be
512 used to overwrite valuable files!
514 * Sample scripts to generate graphs reside in `contrib/' in the source
515 package or somewhere near `/usr/share/doc/collectd' in most distributions.
516 Please be aware that those script are meant as a starting point for your
517 own experiments.. Some of them require the `RRDs' Perl module.
518 (`librrds-perl' on Debian) If you have written a more sophisticated
519 solution please share it with us.
521 * The RRAs of the automatically created RRD files depend on the `step'
522 and `heartbeat' settings given. If change these settings you may need to
523 re-create the files, losing all data. Please be aware of that when changing
524 the values and read the rrdtool(1) manpage thoroughly.
527 collectd and chkrootkit
528 -----------------------
530 If you are using the `dns' plugin chkrootkit(1) will report collectd as a
531 packet sniffer ("<iface>: PACKET SNIFFER(/usr/sbin/collectd[<pid>])"). The
532 plugin captures all UDP packets on port 53 to analyze the DNS traffic. In
533 this case, collectd is a legitimate sniffer and the report should be
534 considered to be a false positive. However, you might want to check that
535 this really is collectd and not some other, illegitimate sniffer.
538 Prerequisites
539 -------------
541 To compile collectd from source you will need:
543 * Usual suspects: C compiler, linker, preprocessor, make, ...
545 * A POSIX-threads (pthread) implementation.
546 Since gathering some statistics is slow (network connections, slow devices,
547 etc) the collectd is parallelized. The POSIX threads interface is being
548 used and should be found in various implementations for hopefully all
549 platforms.
551 * CoreFoundation.framework and IOKit.framework (optional)
552 For compiling on Darwin in general and the `apple_sensors' plugin in
553 particular.
554 <http://developer.apple.com/corefoundation/>
556 * libclntsh (optional)
557 Used by the `oracle' plugin.
559 * libcredis (optional)
560 Used by the redis plugin. Please note that you require a 0.2.2 version
561 or higher. <http://code.google.com/p/credis/>
563 * libcurl (optional)
564 If you want to use the `apache', `ascent', `curl', `nginx', or `write_http'
565 plugin.
566 <http://curl.haxx.se/>
568 * libdbi (optional)
569 Used by the `dbi' plugin to connect to various databases.
570 <http://libdbi.sourceforge.net/>
572 * libesmtp (optional)
573 For the `notify_email' plugin.
574 <http://www.stafford.uklinux.net/libesmtp/>
576 * libganglia (optional)
577 Used by the `gmond' plugin to process data received from Ganglia.
578 <http://ganglia.info/>
580 * libgcrypt (optional)
581 Used by the `network' plugin for encryption and authentication.
582 <http://www.gnupg.org/>
584 * libhal (optional)
585 If present, the uuid plugin will check for UUID from HAL.
586 <http://hal.freedesktop.org/>
588 * libiptc (optional)
589 For querying iptables counters.
590 <http://netfilter.org/>
592 If not found on the system, a version shipped with this distribution can
593 be used. It requires some Linux headers in /usr/include/linux. You can
594 force the build system to use the shipped version by specifying
595 --with-libiptc=shipped
596 when running the configure script.
598 * libjvm (optional)
599 Library that encapsulates the `Java Virtual Machine' (JVM). This library is
600 used by the Java plugin to execute Java bytecode. See “Configuring with
601 libjvm” below.
602 <http://openjdk.java.net/> (and others)
604 * libmemcached (optional)
605 Used by the `memcachec' plugin to connect to a memcache daemon.
606 <http://tangent.org/552/libmemcached.html>
608 * libmodbus (optional)
609 Used by the “modbus” plugin to communicate with Modbus/TCP devices. The
610 “modbus” plugin works with version 2.0.3 of the library – due to frequent
611 API changes other versions may or may not compile cleanly.
612 <http://www.libmodbus.org/>
614 * libmysqlclient (optional)
615 Unsurprisingly used by the `mysql' plugin.
616 <http://dev.mysql.com/>
618 * libnetapp (optional)
619 Required for the “netapp” plugin.
620 This library is part of the “Manage ONTAP SDK” published by NetApp.
622 * libnetlink (optional)
623 Used, obviously, for the `netlink' plugin.
624 <http://www.linuxfoundation.org/en/Net:Iproute2>
626 * libnetsnmp (optional)
627 For the `snmp' plugin.
628 <http://www.net-snmp.org/>
630 * libnotify (optional)
631 For the `notify_desktop' plugin.
632 <http://www.galago-project.org/>
634 * liboping (optional)
635 Used by the `ping' plugin to send and receive ICMP packets.
636 <http://verplant.org/liboping/>
638 * libowcapi (optional)
639 Used by the `onewire' plugin to read values from onewire sensors (or the
640 owserver(1) daemon).
641 <http://www.owfs.org/>
643 * libpcap (optional)
644 Used to capture packets by the `dns' plugin.
645 <http://www.tcpdump.org/>
647 * libperfstat (optional)
648 Used by various plugins to gather statistics under AIX.
650 * libperl (optional)
651 Obviously used by the `perl' plugin. The library has to be compiled with
652 ithread support (introduced in Perl 5.6.0).
653 <http://www.perl.org/>
655 * libpq (optional)
656 The PostgreSQL C client library used by the `postgresql' plugin.
657 <http://www.postgresql.org/>
659 * libprotobuf-c, protoc-c (optional)
660 Used by the `pinba' plugin to generate a parser for the network packets
661 sent by the Pinba PHP extension.
662 <http://code.google.com/p/protobuf-c/>
664 * libpython (optional)
665 Used by the `python' plugin. Currently, Python 2.3 and later and Python 3
666 are supported.
667 <http://www.python.org/>
669 * librabbitmq (optional; also called “rabbitmq-c”)
670 Used by the AMQP plugin for AMQP connections, for example to RabbitMQ.
671 <http://hg.rabbitmq.com/rabbitmq-c/>
673 * librouteros (optional)
674 Used by the `routeros' plugin to connect to a device running `RouterOS'.
675 <http://verplant.org/librouteros/>
677 * librrd (optional)
678 Used by the `rrdtool' and `rrdcached' plugins. The latter requires RRDtool
679 client support which was added after version 1.3 of RRDtool. Versions 1.0,
680 1.2 and 1.3 are known to work with the `rrdtool' plugin.
681 <http://oss.oetiker.ch/rrdtool/>
683 * librt, libsocket, libkstat, libdevinfo (optional)
684 Various standard Solaris libraries which provide system functions.
685 <http://developers.sun.com/solaris/>
687 * libsensors (optional)
688 To read from `lm_sensors', see the `sensors' plugin.
689 <http://www.lm-sensors.org/>
691 * libstatgrab (optional)
692 Used by various plugins to collect statistics on systems other than Linux
693 and/or Solaris.
694 <http://www.i-scream.org/libstatgrab/>
696 * libtokyotyrant (optional)
697 Used by the tokyotyrant plugin.
698 <http://1978th.net/tokyotyrant/>
700 * libupsclient/nut (optional)
701 For the `nut' plugin which queries nut's `upsd'.
702 <http://networkupstools.org/>
704 * libvirt (optional)
705 Collect statistics from virtual machines.
706 <http://libvirt.org/>
708 * libxml2 (optional)
709 Parse XML data. This is needed for the `ascent' and `libvirt' plugins.
710 <http://xmlsoft.org/>
712 * libxmms (optional)
713 <http://www.xmms.org/>
715 * libyajl (optional)
716 Parse JSON data. This is needed for the `curl_json' plugin.
717 <http://github.com/lloyd/yajl>
719 * libvarnish (optional)
720 Fetches statistics from a Varnish instance. This is needed for the Varnish plugin
721 <http://varnish-cache.org>
723 Configuring / Compiling / Installing
724 ------------------------------------
726 To configure, build and install collectd with the default settings, run
727 `./configure && make && make install'. For detailed, generic instructions
728 see INSTALL. For a complete list of configure options and their description,
729 run `./configure --help'.
731 By default, the configure script will check for all build dependencies and
732 disable all plugins whose requirements cannot be fulfilled (any other plugin
733 will be enabled). To enable a plugin, install missing dependencies (see
734 section `Prerequisites' above) and rerun `configure'. If you specify the
735 `--enable-<plugin>' configure option, the script will fail if the depen-
736 dencies for the specified plugin are not met. In that case you can force the
737 plugin to be built using the `--enable-<plugin>=force' configure option.
738 This will most likely fail though unless you're working in a very unusual
739 setup and you really know what you're doing. If you specify the
740 `--disable-<plugin>' configure option, the plugin will not be built. If you
741 specify the `--enable-all-plugins' or `--disable-all-plugins' configure
742 options, all plugins will be enabled or disabled respectively by default.
743 Explicitly enabling or disabling a plugin overwrites the default for the
744 specified plugin. These options are meant for package maintainers and should
745 not be used in everyday situations.
747 By default, collectd will be installed into `/opt/collectd'. You can adjust
748 this setting by specifying the `--prefix' configure option - see INSTALL for
749 details. If you pass DESTDIR=<path> to `make install', <path> will be
750 prefixed to all installation directories. This might be useful when creating
751 packages for collectd.
753 Configuring with libjvm
754 -----------------------
756 To determine the location of the required files of a Java installation is not
757 an easy task, because the locations vary with your kernel (Linux, SunOS, …)
758 and with your architecture (x86, SPARC, …) and there is no ‘java-config’
759 script we could use. Configuration of the JVM library is therefore a bit
760 tricky.
762 The easiest way to use the `--with-java=$JAVA_HOME' option, where
763 `$JAVA_HOME' is usually something like:
764 /usr/lib/jvm/java-1.5.0-sun-1.5.0.14
766 The configure script will then use find(1) to look for the following files:
768 - jni.h
769 - jni_md.h
770 - libjvm.so
772 If found, appropriate CPP-flags and LD-flags are set and the following
773 library checks succeed.
775 If this doesn't work for you, you have the possibility to specify CPP-flags,
776 C-flags and LD-flags for the ‘Java’ plugin by hand, using the following three
777 (environment) variables:
779 - JAVA_CPPFLAGS
780 - JAVA_CFLAGS
781 - JAVA_LDFLAGS
783 For example (shortened for demonstration purposes):
785 ./configure JAVA_CPPFLAGS="-I$JAVA_HOME/include -I$JAVA_HOME/include/linux"
787 Adding "-ljvm" to the JAVA_LDFLAGS is done automatically, you don't have to
788 do that.
790 Crosscompiling
791 --------------
793 To compile correctly collectd needs to be able to initialize static
794 variables to NAN (Not A Number). Some C libraries, especially the GNU
795 libc, have a problem with that.
797 Luckily, with GCC it's possible to work around that problem: One can define
798 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
799 ``implementation'' the configure script needs to compile and run a short
800 test program. Obviously running a test program when doing a cross-
801 compilation is, well, challenging.
803 If you run into this problem, you can use the `--with-nan-emulation'
804 configure option to force the use of this implementation. We can't promise
805 that the compiled binary actually behaves as it should, but since NANs
806 are likely never passed to the libm you have a good chance to be lucky.
808 Likewise, collectd needs to know the layout of doubles in memory, in order
809 to craft uniform network packets over different architectures. For this, it
810 needs to know how to convert doubles into the memory layout used by x86. The
811 configure script tries to figure this out by compiling and running a few
812 small test programs. This is of course not possible when cross-compiling.
813 You can use the `--with-fp-layout' option to tell the configure script which
814 conversion method to assume. Valid arguments are:
816 * `nothing' (12345678 -> 12345678)
817 * `endianflip' (12345678 -> 87654321)
818 * `intswap' (12345678 -> 56781234)
821 Contact
822 -------
824 For questions, bug reports, development information and basically all other
825 concerns please send an email to collectd's mailing list at
826 <collectd at verplant.org>.
828 For live discussion and more personal contact visit us in IRC, we're in
829 channel #collectd on freenode.
832 Author
833 ------
835 Florian octo Forster <octo at verplant.org>,
836 Sebastian tokkee Harl <sh at tokkee.org>,
837 and many contributors (see `AUTHORS').
839 Please send bug reports and patches to the mailing list, see `Contact'
840 above.