Zabbix Documentation 4.0

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manual:installation:known_issues

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manual:installation:known_issues [2019/05/17 07:57]
manual:installation:known_issues [2020/02/18 10:19] (current)
martins-v snmp data spikes
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 +==== 7 Known issues ====
  
 +=== Global event correlation ===
 +
 +Events may not get correlated correctly if the time interval between the first and second event is very small, i.e. half a second and less.
 +
 +=== IPMI checks ===
 +
 +IPMI checks will not work with the standard OpenIPMI library package on Debian prior to 9 (stretch) and Ubuntu prior to 16.04 (xenial). To fix that, recompile OpenIPMI library with OpenSSL enabled as discussed in [[https://​support.zabbix.com/​browse/​ZBX-6139|ZBX-6139]].
 +=== SSH checks ===
 +
 +Some Linux distributions like Debian, Ubuntu do not support encrypted private keys (with passphrase) if the libssh2 library is installed from packages. Please see  [[https://​support.zabbix.com/​browse/​ZBX-4850|ZBX-4850]] for more details.
 +
 +=== ODBC checks ===
 +
 +Zabbix server or proxy that uses MySQL as its database may or may not work correctly with MySQL ODBC library due to an [[https://​bugs.mysql.com/​bug.php?​id=73709|upstream bug]]. Please see  [[https://​support.zabbix.com/​browse/​ZBX-7665|ZBX-7665]] for more information and available workarounds.
 +
 +XML data queried from Microsoft SQL Server may get truncated to 2033 characters due to a Microsoft [[https://​support.microsoft.com/​en-us/​help/​310378/​the-xml-data-row-is-truncated-at-2-033-characters-when-you-use-the-sql|issue]].
 +
 +=== HTTPS checks ===
 +
 +Web scenarios and HTTP agent items using the https protocol, Zabbix agent checks ''​net.tcp.service[https...]''​ and ''​net.tcp.service.perf[https...]''​ may fail if the target server is configured to disallow TLS v1.0 protocol or below. ​ Please see  [[https://​support.zabbix.com/​browse/​ZBX-9879|ZBX-9879]] for more information and available workarounds.
 +
 +=== Web monitoring and HTTP agent ===
 +
 +Zabbix server leaks memory on CentOS 6, CentOS 7 and possibly other related Linux distributions due to an [[https://​bugzilla.redhat.com/​show_bug.cgi?​id=1057388|upstream bug]] when %%"​%%SSL verify peer%%"​%% is enabled in web scenarios or HTTP agent. Please see [[https://​support.zabbix.com/​browse/​ZBX-10486|ZBX-10486]] for more information and available workarounds.
 +
 +=== Simple checks ===
 +
 +There is a bug in **fping** versions earlier than v3.10 that mishandles duplicate echo replay packets. This may cause unexpected results for ''​icmpping'',​ ''​icmppingloss'',​ ''​icmppingsec''​ items. It is recommended to use the latest version of **fping**. Please see  [[https://​support.zabbix.com/​browse/​ZBX-11726|ZBX-11726]] for more details.
 +
 +=== SNMP checks ===
 +
 +If the OpenBSD operating system is used, a use-after-free bug in the Net-SNMP library up to the 5.7.3 version can cause a crash of Zabbix server if the SourceIP parameter is set in the Zabbix server configuration file. As a workaround, please do not set the SourceIP parameter. The same problem applies also for Linux, but it does not cause Zabbix server to stop working.
 +A local patch for the net-snmp package on OpenBSD was applied and will be released with OpenBSD 6.3.
 +
 +=== SNMP data spikes ===
 +
 +Spikes in SNMP data have been observed that may be related to certain physical factors like voltage spikes in the mains. See [[https://​support.zabbix.com/​browse/​ZBX-14318|ZBX-14318]] more details.
 +
 +=== Alerter process crash in Centos/RHEL 7 ===
 +
 +Instances of a Zabbix server alerter process crash have been encountered in Centos/RHEL 7. Please see [[https://​support.zabbix.com/​browse/​ZBX-10461|ZBX-10461]] for details.
 +
 +=== Compiling Zabbix agent on HP-UX ===
 +
 +If you install the PCRE library from a popular HP-UX package site http://​hpux.connect.org.uk,​ for example from file ''​pcre-8.42-ia64_64-11.31.depot'',​ you get only the 64-bit version of the library installed in the /​usr/​local/​lib/​hpux64 directory.
 +
 +In this case, for successful agent compilation customized options need to be used for the %%"​%%configure%%"​%% script, e.g.: 
 +
 +  CFLAGS="​+DD64"​ ./configure --enable-agent --with-libpcre-include=/​usr/​local/​include --with-libpcre-lib=/​usr/​local/​lib/​hpux64
 +
 +=== Flipping frontend locales ===
 +
 +It has been observed that frontend locales may flip without apparent logic, i. e. some pages (or parts of pages) are displayed in one language while other pages (or parts of pages) in a different language. Typically the problem may appear when there are several users, some of whom use one locale, while others use another.
 +
 +A known workaround to this is to disable multithreading in PHP and Apache.
 +
 +The problem is related to how setting the locale works [[https://​www.php.net/​manual/​en/​function.setlocale|in PHP]]: locale information is maintained per process, not per thread. So in a multi-thread environment,​ when there are several projects run by same Apache process, it is possible that the locale gets changed in another thread and that changes how data can be processed in the Zabbix thread.
 +
 +For more information,​ please see related problem reports:
 +
 +  * [[https://​support.zabbix.com/​browse/​ZBX-10911|ZBX-10911]] (Problem with flipping frontend locales)
 +  * [[https://​support.zabbix.com/​browse/​ZBX-16297|ZBX-16297]] (Problem with number processing in graphs using the ''​bcdiv''​ function of BC Math functions)
 +
 +=== Compatibility issue with PHP 7.0 ===
 +
 +It has been observed that with PHP 7.0 importing a template with web monitoring triggers may fail due to incorrectly added double quotes to the web monitoring items in the trigger expressions. The issue goes away when upgrading PHP to 7.1.
 +
 +=== PHP 7.3 opcache configuration ===
 +
 +If %%"​%%opcache%%"​%% is enabled in the PHP 7.3 configuration,​ Zabbix frontend may show a blank screen when loaded for the first time. This is a registered [[https://​bugs.php.net/​bug.php?​id=78015|PHP bug]]. To work around this, please set the %%"​%%opcache.optimization_level%%"​%% parameter to ''​0x7FFFBFDF''​ in the PHP configuration (php.ini file).
 +
 +=== Graphs ===
 +
 +Changes to Daylight Saving Time (DST) result in irregularities when displaying X axis labels (date duplication,​ date missing, etc).
 +
 +=== Log file monitoring ===
 +
 +''​log[]''​ and ''​logrt[]''​ items repeatedly reread log file from the beginning if file system is 100% full and the log file is being appended (see [[https://​support.zabbix.com/​browse/​ZBX-10884|ZBX-10884]] for more information).
 +
 +=== Slow MySQL queries ===
 +
 +Zabbix server generates slow select queries in case of non-existing values for items. This is caused by a known [[https://​bugs.mysql.com/​bug.php?​id=74602|issue]] in MySQL 5.6/5.7 versions. A workaround to this is disabling the index_condition_pushdown optimizer in MySQL. For an extended discussion, see [[https://​support.zabbix.com/​browse/​ZBX-10652|ZBX-10652]].
 +
 +=== MariaDB row size error ===
 +
 +Prior to MariaDB 10.2.26, 10.3.17, and 10.4.7, MariaDB didn't properly calculate the row sizes while executing DDL, so "​unsafe"​ tables could be created, even with ''​innodb_strict_mode=ON''​ set. This was fixed by [[https://​jira.mariadb.org/​browse/​MDEV-19292|MDEV-19292]]. As a side effect, tables that could be created in previous versions may get rejected after the latest releases.
 +
 +Suggested database changes for existing 4.0 installations:​
 +
 +  shell> mysql -uroot -p<​password>​
 +  mysql> alter table `host_inventory` modify `name` varchar(128) default ''​ not null, modify `alias` varchar(128) default ''​ not null, modify `os` varchar(128) default ''​ not null, modify `os_short` ​  ​varchar(128) default ''​ not null;
 +
 +Suggested database changes for new 4.0 installations:​
 +
 +  shell> mysql -uroot -p<​password>​
 +  mysql> set global innodb_strict_mode='​OFF';​
 +
 +Perform database creation as usual and fix schema after:
 +
 +  shell> mysql -uroot -p<​password>​
 +  mysql> alter table `host_inventory` modify `name` varchar(128) default ''​ not null, modify `alias` varchar(128) default ''​ not null, modify `os` varchar(128) default ''​ not null, modify `os_short` varchar(128) default ''​ not null;
 +  mysql> set global innodb_strict_mode='​ON';​
 +
 +=== API ===
 +
 +The **output** parameter does not work properly with the ''​history.get''​ method.
 +
 +=== API login ===
 +
 +A large number of open user sessions can be created when using custom scripts with the ''​user.login''​ [[:​manual/​api/​reference/​user/​login|method]] without a following ''​user.logout''​.
 +
 +=== IPv6 address issue in SNMPv3 traps ===
 +
 +Due to a net-snmp bug, IPv6 address may not be correctly displayed when using SNMPv3 in SNMP traps. For more details and a possible workaround, see [[https://​support.zabbix.com/​browse/​ZBX-14541|ZBX-14541]].
 +
 +=== IE11 issue with map resizing in dashboard widgets ===
 +
 +Maps, in Internet Explorer 11, are cut off on the right side if the map content is larger than the dashboard widget area (instead of being resized proportionately). This is intentional because of an IE11-related issue with proper resizing of SVG images.
 +
 +=== Known issues in 4.0.0 ===
 +
 +  * Fullscreen mode for the dashboards cannot be accessed with the respective URL parameter: ''/​zabbix.php?​action=dashboard.view&​fullscreen=1''​. Fixed in 4.0.1.
 +  * When filtering triggers in //​Monitoring//​ -> //​Overview//​ (Triggers), trigger severity instead of problem severity is taken into account.
 +
 +=== Known issues in 4.0.0, 4.0.1 ===
 +
 +  * Upgrade to 4.0.0 and 4.0.1 from Zabbix 3.0 does not replace {TRIGGER.NAME} macros to {EVENT.NAME} macros like it should. Fixed for 4.0.2.
 +
 +=== Known issues in 4.0.0 - 4.0.2 ===
 +
 +  * If the //​[[:​manual/​config/​items/​check_now|Check now]]// request is performed from the item list for items that do not support it (template items, active agent items, etc.), a '​Request sent successfully'​ message is displayed even though the functionality does not work for these items. Fixed in 4.0.3, by displaying a corresponding error message.
 +
 +=== Known issues in 4.0.2 ===
 +
 +  * Parent host group selection does not work in the following locations:
 +    * //​Monitoring//​ -> //​Problems//​ filter
 +    * //​Monitoring//​ -> //​Dashboard//​ widgets with host group selection: ​
 +    * //Reports// -> //Triggers top 100// filter
 +
 +=== Known issues in 4.0.0 - 4.0.3 ===
 +
 +  * Time suffixes do not work in constants of calculated item formulas. Fixed in 4.0.4.
 +  * [[:​manual/​web_interface/​frontend_sections/​monitoring/​problems#​negative_problem_duration|Negative problem duration]] affects the total result in [[:​manual/​it_services|SLA calculation]] or [[:​manual/​web_interface/​frontend_sections/​reports/​availability|Availability report]], making it incorrect. Fixed in 4.0.4.
 +
 +=== Known issues in 4.0.3 ===
 +
 +  * If an item is deleted that has a low-level discovery created trigger, the trigger is not deleted. This leads to %%"​%%orphaned%%"​%% problems (with no item/host) being displayed in the problem view. Similarly, if an item is deleted that has low-level discovery created dependent item, the dependent item is not deleted. Fixed in 4.0.4.
 +
 +=== Known issues starting with 4.0.3 ===
 +
 +  * Failed login attempt message has been changed to display only the first 39 characters of a stored IP address as that's the character limit in the database field. That means that IPv6 IP addresses longer than 39 characters will be shown incompletely.
 +
 +=== Known issues in 4.0.0 - 4.0.5 ===
 +
 +  * ''​net.dns[]''​ Zabbix agent [[:​manual/​config/​items/​itemtypes/​zabbix_agent|item]] does not support IPv6 addresses in its first parameter. Fixed in 4.0.6.
 +
 +=== Known issues in 4.0.6, 4.0.7 ===
 +
 +  * IPMI pollers are unable to process more than 60 items per minute. Fixed in 4.0.8.
 +  * You may encounter the issue of 100% CPU usage by IPMI pollers if using OpenIPMI version 2.0.26 and above. Fixed in 4.0.8.
 +
 +=== Known issues in 4.0.8 ===
 +
 +  * This version requires //write// permissions to the ''​assets''​ directory for the web server user. This requirement,​ however, would break those installations of the frontend where the web server has no write permissions to the document root (see [[https://​support.zabbix.com/​browse/​ZBX-16180|ZBX-16180]] for details). As a result, this requirement is rolled back in 4.0.9.
 +
 +=== Known issues in 4.0.0 - 4.0.15 ===
 +
 +  * High memory usage has been observed during process startup with SQLite 3.7.17 on Centos/RHEL 7. The startup process has been improved in 4.0.16 to avoid similar issues with other databases as well. See [[https://​support.zabbix.com/​browse/​ZBX-9084|ZBX-9084]] for more details.