collectd bot [Wed, 23 May 2018 11:10:03 +0000 (13:10 +0200)]
Auto-Merge pull request #2793 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Dagobert Michelsen [Wed, 21 Mar 2018 20:22:45 +0000 (21:22 +0100)]
Include kstat.h when available
Ruben Kerkhof [Wed, 16 May 2018 11:24:55 +0000 (13:24 +0200)]
Fix make distcheck on Mac OS
CC src/libcollectdclient/libcollectdclient_la-network_parse.lo
../../src/libcollectdclient/network_parse.c:49:10: fatal error: 'stdendian.h' file not found
^~~~~~~~~~~~~
1 error generated.
Fixes #2608
collectd bot [Wed, 23 May 2018 09:15:47 +0000 (11:15 +0200)]
Auto-Merge pull request #2792 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 20 May 2018 16:24:25 +0000 (23:24 +0700)]
Added missing include of "collectd.h"
This adressed to solve compilation issue on Solaris platform:
./src/config.h:1526:0: error: "_FILE_OFFSET_BITS" redefined [-Werror]
Dagobert Michelsen [Thu, 3 May 2018 10:42:28 +0000 (12:42 +0200)]
Add endianness checks for AIX
collectd bot [Mon, 21 May 2018 06:32:58 +0000 (08:32 +0200)]
Auto-Merge pull request #2788 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Dagobert Michelsen [Thu, 5 Apr 2018 08:49:30 +0000 (10:49 +0200)]
Fix gcc issue on Mac byteorder
Dagobert Michelsen [Wed, 4 Apr 2018 12:34:15 +0000 (14:34 +0200)]
Fix conditional on byteorder to work on Solaris
Dagobert Michelsen [Wed, 21 Mar 2018 21:23:07 +0000 (22:23 +0100)]
Keep clang-format happy
Dagobert Michelsen [Wed, 21 Mar 2018 21:09:15 +0000 (22:09 +0100)]
Add fallback for endianess conversion
collectd bot [Mon, 21 May 2018 04:18:17 +0000 (06:18 +0200)]
Auto-Merge pull request #2787 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Mon, 21 May 2018 03:38:51 +0000 (10:38 +0700)]
Added missing include of 'config.h'
This adressed to solve compilation issue on Solaris platform:
In file included from src/libcollectdclient/network_parse.c:26:0,
from src/libcollectdclient/network_parse_test.c:32:
./src/config.h:1517:0: error: "_FILE_OFFSET_BITS" redefined
collectd bot [Sun, 20 May 2018 20:22:12 +0000 (22:22 +0200)]
Auto-Merge pull request #2786 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 20 May 2018 19:35:44 +0000 (02:35 +0700)]
Added missing include of 'kstat.h' and variable declaration
This adressed to solve compilation issue on Solaris platform:
src/daemon/collectd.c:212: error: 'kc' undeclared (first use in this function)
src/daemon/collectd.c:213: error: implicit declaration of function 'kstat_open'
collectd bot [Sun, 20 May 2018 19:21:30 +0000 (21:21 +0200)]
Auto-Merge pull request #2785 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 20 May 2018 17:57:27 +0000 (00:57 +0700)]
Try to make clang-format happy
Pavel Rochnyack [Sun, 20 May 2018 17:52:33 +0000 (00:52 +0700)]
Added missing include of 'kstat.h'
This adressed to solve compilation issue on Solaris platform:
src/utils_vl_lookup.c:37:1: error: unknown type name 'kstat_ctl_t'
kstat_ctl_t *kc;
collectd bot [Sun, 20 May 2018 17:21:04 +0000 (19:21 +0200)]
Auto-Merge pull request #2784 from rpv-tomsk/fix-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 20 May 2018 16:48:00 +0000 (23:48 +0700)]
Added missing include of 'kstat.h'
This adressed to solve compilation issue on Solaris platform:
src/daemon/common.c:64:8: error: unknown type name 'kstat_ctl_t'
extern kstat_ctl_t *kc;
Ruben Kerkhof [Fri, 18 May 2018 16:43:47 +0000 (18:43 +0200)]
Merge pull request #2681 from elfiesmelfie/feat_pmu_cores
intel_pmu: core groups feature
Kamil Wiatrowski [Thu, 17 May 2018 14:15:24 +0000 (15:15 +0100)]
intel_pmu plugin: fix for PR comments
Check for failure from snprintf.
Make cgroup and event const in pmu_submit_counter.
Change-Id: I5547375da26c3a63b76588b733e844e3199e9bb8
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Pavel Rochnyak [Wed, 16 May 2018 12:25:13 +0000 (19:25 +0700)]
Merge pull request #2742 from elfiesmelfie/ipmi_bugfix_sensor_option
ipmi plugin: Fix for segmentation fault for wrong data type in Sensor section.
Mariusz Szafranski [Thu, 29 Mar 2018 08:45:46 +0000 (09:45 +0100)]
ipmi plugin: Fix for segmentation fault for wrong data type in Sensor section.
Incorrect, malicious data in the Sensor section can cause a segmentation fault.
Error message is generated instead of crash after applying this patch.
Change-Id: Ibc387b5594f9453f1fc957ed37ceb09cfa34ded5
Signed-off-by: Mariusz Szafranski <mariuszx.szafranski@intel.com>
Marc Fournier [Tue, 15 May 2018 13:37:45 +0000 (14:37 +0100)]
Merge pull request #2776 from mfournier/unblock_pr_2737
Unblock #2737
Marc Fournier [Tue, 15 May 2018 12:06:02 +0000 (14:06 +0200)]
Trigger Jenkins
collectd bot [Tue, 1 May 2018 09:12:01 +0000 (11:12 +0200)]
Auto-Merge pull request #2760 from rpv-tomsk/tmpfix
Automatically merged due to "Automerge" label
Pavel Rochnyack [Tue, 1 May 2018 08:30:43 +0000 (15:30 +0700)]
docs: Fix typo in collectd.conf.pod
collectd bot [Thu, 29 Mar 2018 19:17:13 +0000 (21:17 +0200)]
Auto-Merge pull request #2736 from rpv-tomsk/collectd-collectd-5.8
Automatically merged due to "Automerge" label
Pavel Rochnyack [Thu, 29 Mar 2018 18:27:14 +0000 (01:27 +0700)]
uuid plugin: Fixed hostname setting
Closes: #2723
References: #2467
Pavel Rochnyak [Wed, 28 Mar 2018 15:26:21 +0000 (22:26 +0700)]
Merge pull request #2703 from elfiesmelfie/fix_ipmi_bugfix_0.2
Fixes for ipmi plugin
collectd bot [Wed, 28 Mar 2018 14:12:50 +0000 (16:12 +0200)]
Auto-Merge pull request #2734 from rpv-tomsk/fix-2732
Automatically merged due to "Automerge" label
Pavel Rochnyack [Wed, 28 Mar 2018 13:23:32 +0000 (20:23 +0700)]
perl plugin: Fix compile fail with message "void function cannot return value"
Closes: #2732
Mariusz Szafranski [Wed, 7 Mar 2018 09:58:43 +0000 (09:58 +0000)]
Revert "ipmi plugin: Ignore events from ignored sensors"
This reverts commit
cd660c5b07b6f09d165435f240ca17d118a1e452.
Mariusz Szafranski [Wed, 7 Mar 2018 09:57:50 +0000 (09:57 +0000)]
Revert "ipmi plugin: Remove duplicate/unused code and unneeded brackets."
This reverts commit
8c9d64bf7615875b5030127b4df68a620e084f0d.
Mariusz Szafranski [Mon, 5 Mar 2018 15:04:10 +0000 (15:04 +0000)]
ipmi plugin: Remove duplicate/unused code and unneeded brackets.
Change-Id: Ia4298f75f59e697df25d05091adbb556b64869e1
Signed-off-by: Mariusz Szafranski <mariuszx.szafranski@intel.com>
Mariusz Szafranski [Thu, 1 Mar 2018 12:09:19 +0000 (12:09 +0000)]
ipmi plugin: Threshold event handler registration fix
This patch fixes registration of threshold event handler for
specific sensor types (e.g. 'System Airflow')
Change-Id: I437f3fe68fecf264adb32a4e2ef4ac214a7e87a4
Signed-off-by: Mariusz Szafranski <mariuszx.szafranski@intel.com>
Mariusz Szafranski [Thu, 1 Mar 2018 12:08:47 +0000 (12:08 +0000)]
ipmi plugin: Ignore events from ignored sensors
Reading is disabled for ignored sensors. This fix it to also
ignore events from s4ensors on ignore list.
Change-Id: I705593c79274a00456a786698452cd3c1bae9872
Signed-off-by: Mariusz Szafranski <mariuszx.szafranski@intel.com>
Mariusz Szafranski [Thu, 1 Mar 2018 12:07:56 +0000 (12:07 +0000)]
ipmi plugin: Fix crash in ipmi.so (interval < 0.5)
Fixes crash (divide by 0) in ipmi.so when plugin related interval
set to 0.45 or less.
Change-Id: I3ac2282efdc005edefe92f870ac30417451c202c
Signed-off-by: Mariusz Szafranski <mariuszx.szafranski@intel.com>
Kamil Wiatrowski [Thu, 22 Feb 2018 15:18:54 +0000 (15:18 +0000)]
intel_pmu plugin: fix for minor issues
Fix minor issues found during review.
Update year to 2018,
add include in utils_config_cores.h to avoid forward
declaration.
Change-Id: I7d657bab7c97d7193d7977ef129181cad13d73d5
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Kamil Wiatrowski [Mon, 19 Feb 2018 13:24:10 +0000 (13:24 +0000)]
intel_pmu plugin: fix for compatibility issue with collectd 5.8
Add definition for PRIsz macro to make code backward compatible with
collectd-5.8 branch.
Change-Id: I880340af5ae883a444563422b3e9975b3693683c
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Kamil Wiatrowski [Mon, 12 Feb 2018 11:12:44 +0000 (11:12 +0000)]
intel_pmu: fix epel6 compilation issue
To avoid compilation error on some versions of gcc the
saveptr for strtok_r needs to be initilised to NULL.
Change-Id: I7b30e51ecae33a6994ba7ea181cac0f33eef023f
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Kamil Wiatrowski [Fri, 2 Feb 2018 14:25:56 +0000 (14:25 +0000)]
intel_pmu,intel_rdt plugins: apply formatting rules
Run script contrib/format.sh to format the code.
Replace zu with new collectd macro PRIsz.
Change-Id: I167b1065461e924d7ab260a35f85f5ab162c4165
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Kamil Wiatrowski [Thu, 2 Nov 2017 13:12:45 +0000 (13:12 +0000)]
intel_rdt: remove redundant code with utils_config_cores
Use utils_config_cores for core groups configuration so it is
in line with intel_pmu and reduce amount of redundant code.
Change-Id: If02e2eeea8bcf3e0df705ebcd9a6310b549b5ebe
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Kamil Wiatrowski [Tue, 8 Aug 2017 14:04:46 +0000 (15:04 +0100)]
intel_pmu plugin: implement core groups option
Having this option will allow to configure monitoring of PMU
events only on specific CPUs thus decrease number of opened
descriptors significantly and avoid 'Too many open files' errors.
New "Cores" option is similar to that available in intel_rdt plugin.
New tool utils_config_cores is added to parse "Cores" option.
Change-Id: I8f792e1f2560c4cf19aee101fdb07c925d682778
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Pavel Rochnyak [Mon, 12 Feb 2018 08:20:10 +0000 (15:20 +0700)]
Merge pull request #2676 from elfiesmelfie/fix_intel_pmu_crash
intel_pmu: fix for possible null pointer dereference
Kamil Wiatrowski [Mon, 5 Feb 2018 13:57:13 +0000 (13:57 +0000)]
intel_pmu: fix for possible null pointer dereference
Null pointer dereference could occur for invalid first hardware event.
In pmu_add_hw_events if the first event was not resolved, on the second
iteration the eventlist_last could be dereferenced to mark previous
event as group leader.
Change-Id: Ic2a2a3572d6835ca892d71f3e66812f356592d9e
Signed-off-by: Kamil Wiatrowski <kamilx.wiatrowski@intel.com>
Pavel Rochnyak [Sat, 10 Feb 2018 11:23:08 +0000 (18:23 +0700)]
Merge pull request #2684 from rpv-tomsk/fix-2673
write_prometheus: Set SO_REUSEADDR on listening socket
Pavel Rochnyak [Sat, 10 Feb 2018 11:19:02 +0000 (18:19 +0700)]
Merge pull request #2613 from elfiesmelfie/update_dpdk_note
docs: update dpdkstats documentation
Pavel Rochnyack [Sat, 10 Feb 2018 10:46:30 +0000 (17:46 +0700)]
write_prometheus: Set SO_REUSEADDR on listening socket
Otherwise Collectd fails to bind the socket after restart.
Thanks to Richard Weinberger and Brandon Hume for reporting.
Closes: #2570
Closes: #2673
collectd bot [Sat, 10 Feb 2018 10:12:50 +0000 (11:12 +0100)]
Auto-Merge pull request #2683 from rpv-tomsk/fix-2607
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sat, 10 Feb 2018 09:20:41 +0000 (09:20 +0000)]
write_kafka: 'rd_kafka_errno2err' is deprecated, fix failed builds
Since librdkafka-0.11.0 applications should use rd_kafka_last_error()
to retrieve the error code from the legacy APIs.
Thanks to hikdo.
Closes: #2607
Closes: #2628
Closes: #2640
Maryam Tahhan [Fri, 26 Jan 2018 11:41:57 +0000 (11:41 +0000)]
Update BUILD.dpdkstat.md
fixed trailing word "Version"
collectd bot [Tue, 19 Dec 2017 14:09:45 +0000 (15:09 +0100)]
Auto-Merge pull request #2629 from rpv-tomsk/fix-2626
Automatically merged due to "Automerge" label
Pavel Rochnyack [Tue, 19 Dec 2017 13:30:12 +0000 (20:30 +0700)]
ipmi plugin: Fix broken 'Sensor' configuration option
collectd bot [Thu, 14 Dec 2017 15:05:23 +0000 (16:05 +0100)]
Auto-Merge pull request #2611 from rpv-tomsk/fix-2587
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 10 Dec 2017 17:14:01 +0000 (17:14 +0000)]
tail plugin, latency: Fix regressions after #2535
- Remove two fixed decimal places from type instance of percentiles
- Recover accuracy of bounds in type instance of buckets
+ Allow (compared to state before #2535) to report percentiles with fractional values
* Changed maximum length of reported type and type instance to 50 chars
References: #2535
Closes: #2587
Maryam Tahhan [Tue, 12 Dec 2017 16:36:52 +0000 (16:36 +0000)]
docs: dpdk extended the initial note
Maryam Tahhan [Mon, 11 Dec 2017 16:14:20 +0000 (16:14 +0000)]
docs: update dpdkstats documentation
Update the dpdkstats documentation to state that it shouldn't be used with
OVS-with-DPDK. The Open vSwitch plugins is what should be used.
Signed-off-by: Maryam Tahhan <maryam.tahhan@intel.com>
collectd bot [Sun, 10 Dec 2017 21:10:59 +0000 (22:10 +0100)]
Auto-Merge pull request #2612 from rpv-tomsk/collectd-5.8-memcached
Automatically merged due to "Automerge" label
Pavel Rochnyack [Sun, 10 Dec 2017 20:24:33 +0000 (03:24 +0700)]
memcached: Check for closed connection to avoid deadloop
Check for 'recv(...) == 0' condition was missing.
Toshiaki Takahashi [Wed, 6 Dec 2017 12:19:41 +0000 (12:19 +0000)]
df: fix memory leak in error case
Because the memory of the STATANYFS list is not released
when the read callback function error occurs,
a memory leak may occur.
With this change, the memory is always released
by not returning in the loop.
Signed-off-by: Florian Forster <octo@collectd.org>
Florian Forster [Thu, 7 Dec 2017 16:10:05 +0000 (17:10 +0100)]
Merge branch 'collectd-5.7' into collectd-5.8
Florian Forster [Thu, 7 Dec 2017 16:06:49 +0000 (17:06 +0100)]
Makefile.am: Fix out-of-tree builds.
Fixes: #2602
Florian Forster [Tue, 5 Dec 2017 15:58:29 +0000 (16:58 +0100)]
liboconfig: Coding style changes.
Mostly whitespace.
Florian Forster [Tue, 5 Dec 2017 15:56:53 +0000 (16:56 +0100)]
liboconfig: Improve error handling.
* Use the YYERROR macro instead of exit(3).
* Remove newlines from strings passed to yyerror().
* Change return valud or yyerror() from int to void.
Florian Forster [Tue, 5 Dec 2017 15:53:34 +0000 (16:53 +0100)]
liboconfig: Check return values of calloc() and realloc().
CID: 38123
Florian Forster [Tue, 5 Dec 2017 15:50:33 +0000 (16:50 +0100)]
email plugin: Avoid strtok_r to tokenize input.
Coverity (wrongly) thinks that "type" might have been NULL (since its
first argument is non-NULL, this cannot happen). It has a point about
insufficient NULL-ness checks, though, as "tmp" may very well be NULL and
we're passing it to atoi() which will likely not take this well.
CID: 37988
Florian Forster [Mon, 4 Dec 2017 08:53:48 +0000 (09:53 +0100)]
Merge pull request #2590 from maryamtahhan/fix_collectd_ovs_deadlock
Fix collectd ovs deadlock
Aleksei Zakharov [Fri, 1 Dec 2017 16:07:04 +0000 (19:07 +0300)]
ceph plugin: Fix #2572
Signed-off-by: Florian Forster <octo@collectd.org>
Florian Forster [Mon, 4 Dec 2017 07:23:26 +0000 (08:23 +0100)]
Merge branch 'collectd-5.7' into collectd-5.8
Florian Forster [Mon, 4 Dec 2017 07:18:33 +0000 (08:18 +0100)]
table plugin: Add explicit NULL checks to clear functions.
CID: 37966
Florian Forster [Fri, 1 Dec 2017 20:05:00 +0000 (21:05 +0100)]
exec plugin: Check return value of plugin_thread_create().
CID: 37942, 37943
Florian Forster [Fri, 1 Dec 2017 19:45:04 +0000 (20:45 +0100)]
rrdtool plugin: Check return value of c_avl_get().
CID: 37940
collectd bot [Fri, 1 Dec 2017 15:14:57 +0000 (16:14 +0100)]
Auto-Merge pull request #2589 from octo/cid/37960
Automatically merged due to "Automerge" label
Tahhan, Maryam [Wed, 29 Nov 2017 12:50:18 +0000 (12:50 +0000)]
utils_ovs: fix #2574
Poll thread was trying to reconnect after event thread was terminated.
Change-Id: I48bf196302139ddf99bb96b49a6c3b4ede345240
Signed-off-by: Mytnyk, Volodymyr <volodymyrx.mytnyk@intel.com>
collectd bot [Fri, 1 Dec 2017 14:20:59 +0000 (15:20 +0100)]
Auto-Merge pull request #2588 from octo/cid/37968
Automatically merged due to "Automerge" label
Florian Forster [Fri, 1 Dec 2017 13:59:55 +0000 (14:59 +0100)]
contrib/format.sh src/perl.c
Florian Forster [Fri, 1 Dec 2017 13:18:50 +0000 (14:18 +0100)]
powerdns plugin: Remove the unused ret_buffer_size argument …
… from powerdns_get_data().
Florian Forster [Fri, 1 Dec 2017 13:30:23 +0000 (14:30 +0100)]
perl plugin: Fix exporting notification meta data.
Previously, the while loop ensured that meta was NULL, causing the for
loop to never been executed. This introduces a new temporary variable to
avoid changing meta before the for loop.
CID: 37960
Florian Forster [Fri, 1 Dec 2017 11:06:26 +0000 (12:06 +0100)]
powerdns plugin: Declare variables on first use.
Florian Forster [Fri, 1 Dec 2017 11:05:21 +0000 (12:05 +0100)]
powerdns plugin: Ensure powerdns_get_data() returns a non-NULL buffer.
Coverity is concerned that if buffer is NULL, strtok_r() is called with
two NULL arguments, causing a NULL pointer dereference.
CID: 37968
Florian Forster [Thu, 30 Nov 2017 16:11:49 +0000 (17:11 +0100)]
Merge branch 'collectd-5.7' into collectd-5.8
collectd bot [Thu, 30 Nov 2017 09:09:13 +0000 (10:09 +0100)]
Auto-Merge pull request #2586 from octo/issue/2583
Automatically merged due to "Automerge" label
Florian Forster [Thu, 30 Nov 2017 08:33:50 +0000 (09:33 +0100)]
network_parse_test.c: Only test security features if libgcrypt is available.
Fixes: #2583
collectd bot [Tue, 28 Nov 2017 08:32:33 +0000 (09:32 +0100)]
Auto-Merge pull request #2580 from octo/cid/179235
Automatically merged due to "Automerge" label
collectd bot [Tue, 28 Nov 2017 08:11:23 +0000 (09:11 +0100)]
Auto-Merge pull request #2579 from octo/cid/179238
Automatically merged due to "Automerge" label
Florian Forster [Tue, 28 Nov 2017 07:24:14 +0000 (08:24 +0100)]
contrib/format.sh src/aggregation.c
Florian Forster [Tue, 28 Nov 2017 07:21:48 +0000 (08:21 +0100)]
aggregation plugin: Check return value of config functions.
CID: 179235
Florian Forster [Tue, 28 Nov 2017 07:17:05 +0000 (08:17 +0100)]
aggregation plugin: Declare variables on initialization.
Florian Forster [Tue, 28 Nov 2017 07:11:07 +0000 (08:11 +0100)]
virt plugin: Remove `do {} while(0)` loop around macro.
The `continue` in the macro was supposed to continue the `for` loop, but
was (unexpectedly) exiting the do…while loop instead.
CID: 179238
collectd bot [Mon, 27 Nov 2017 21:10:38 +0000 (22:10 +0100)]
Auto-Merge pull request #2576 from octo/collectd-5.8
Automatically merged due to "Automerge" label
Florian Forster [Mon, 27 Nov 2017 20:09:14 +0000 (21:09 +0100)]
contrib/format.sh: Switch to custom domain name.
collectd bot [Sat, 25 Nov 2017 08:18:51 +0000 (09:18 +0100)]
Auto-Merge pull request #2575 from octo/cid/37934
Automatically merged due to "Automerge" label
Florian Forster [Sat, 25 Nov 2017 07:28:35 +0000 (08:28 +0100)]
ping plugin: Lock the mutex later.
Coverity gets confused if holding the lock while allocating pingobj.
CID: 37934
collectd bot [Wed, 22 Nov 2017 07:14:52 +0000 (08:14 +0100)]
Auto-Merge pull request #2568 from octo/cid/157645
Automatically merged due to "Automerge" label
Florian Forster [Wed, 22 Nov 2017 06:47:14 +0000 (07:47 +0100)]
set target: Fix memory leak.
CID: 157645
collectd bot [Tue, 21 Nov 2017 16:08:21 +0000 (17:08 +0100)]
Auto-Merge pull request #2566 from octo/pr/2556
Automatically merged due to "Automerge" label
Florian Forster [Tue, 21 Nov 2017 09:38:52 +0000 (10:38 +0100)]
Merge branch 'collectd-5.7' into collectd-5.8
Miroslav Lichvar [Mon, 20 Nov 2017 11:02:44 +0000 (12:02 +0100)]
rrd plugin: Fix writing of long values.
The buffer provided for value_list_to_string() was not long enough to
fit a timestamp and a negative value using exponent and maximum
precision of the gauge format.
Signed-off-by: Florian Forster <octo@collectd.org>