7 Problèmes connus

Corrélation d’événements

Les événements peuvent ne pas être corrélés correctement si l'intervalle de temps entre le premier et le deuxième événement est trop petit, c'est-à-dire une demi-seconde et moins.

. #### Installation from packages

It has been observed that it is impossible to install a specific frontend version by running, e.g.:

yum install -v zabbix-web-mysql-scl-5.0.0

As a workaround to this issue, if you wish to install a specific frontend version, specify version for all components, e.g.:

yum install zabbix-web-mysql-scl-5.0.0 zabbix-apache-conf-scl-5.0.0 zabbix-web-5.0.0 zabbix-web-deps-scl-5.0.0

Vérifications IPMI

Les vérifications IPMI ne fonctionneront pas avec le paquet de la bibliothèque standard OpenIPMI sur Debian avant 9 (stretch) et Ubuntu avant 16.04 (xenial). Pour résoudre ce problème, recompilez la bibliothèque OpenIPMI avec OpenSSL activé comme indiqué dans ZBX-6139.

Vérifications SSH

Certaines distributions Linux comme Debian et Ubuntu ne supportent pas les clés privées cryptées (avec phrase secrète) si la bibliothèque libssh2 est installée à partir des packages. Voir ZBX-4850 pour plus de détails.

Vérifications ODBC

Le serveur Zabbix ou le proxy qui utilise MySQL comme base de données peut ou ne peut pas fonctionner correctement avec la bibliothèque MySQL ODBC en raison d'un bug en amont. Voir ZBX-7665 pour plus d'informations et les solutions de contournement disponibles.

Les données XML interrogées à partir de Microsoft SQL Server peuvent être tronquées à 2033 caractères en raison d'un problème Microsoft.

Vérifications HTTPS

Les scénarios Web utilisant le protocole https et les vérifications d'agent Zabbix net.tcp.service[https…] et net.tcp.service.perf[https…] peuvent échouer si le serveur cible est configuré pour interdire le protocole TLS v1.0 ou inférieur. Voir ZBX-9879 pour plus d'informations et les solutions de contournement disponibles.

Possible deadlocks with MySQL/MariaDB

When running under high load, and with more than one LLD worker involved, it is possible to run into a deadlock caused by an InnoDB error related to the row-locking strategy (see upstream bug). The error has been fixed in MySQL since 8.0.29, but not in MariaDB. For more details, see ZBX-21506.

Web monitoring and HTTP agent

Zabbix server leaks memory on CentOS 6, CentOS 7 and possibly other related Linux distributions due to an upstream bug when "SSL verify peer" is enabled in web scenarios or HTTP agent. Please see ZBX-10486 for more information and available workarounds.

Vérifications Simples

Un bug existe dans les versions de fping antérieures à la version v3.10 release 2.1.2 qui traite mal les paquets echo replay dupliqués. Cela peut provoquer des résultats inattendus pour les éléments icmpping, icmppingloss, icmppingsec. Il est recommandé d'utiliser la dernière version de fping. Voir ZBX-11726 pour plus de détails.

Vérifications SNMP

Si le système d'exploitation OpenBSD est utilisé, un bug dans la bibliothèque Net-SNMP jusqu'à la version 5.7.3 peut provoquer un plantage du serveur Zabbix si le paramètre SourceIP est défini dans le fichier de configuration du serveur Zabbix. Pour contourner le problème, ne définissez pas le paramètre SourceIP. Le même problème s'applique également à Linux, mais cela n'empêche pas le serveur Zabbix de fonctionner. Un correctif local pour le package net-snmp sur OpenBSD a été appliqué et sera publié avec OpenBSD 6.3.

Problème de compatibilité avec PHP 7.0

Il a été observé qu'avec PHP 7.0, l'importation d'un modèle avec des déclencheurs de surveillance Web peut échouer en raison de l'ajout incorrect de doubles guillemets aux éléments de surveillance Web dans les expressions de déclencheur. Le problème disparaît lors de la mise à jour de PHP vers la version 7.1.

Graphiques

Les modifications apportées à l'heure d'été (DST) entraînent des irrégularités lors de l'affichage des libellés de l'axe X (duplicat de date, date manquante, etc.).

Supervision de fichier journaux

Les éléments log[] et logrt[] relisent de manière répétée le fichier de logs depuis le début si le système de fichiers est plein à 100% et que de nouvelles entrées sont ajoutées au fichier journal (voir ZBX-10884 pour plus d'informations).

Requêtes MySQL lentes

Le serveur Zabbix génère des requêtes SELECT lentes en cas de valeurs non existantes pour les éléments. Ceci est dû à un problème connu dans les versions MySQL 5.6/5.7. Une solution de contournement consiste à désactiver l'optimiseur index_condition_pushdown dans MySQL. Pour une discussion approfondie, voir ZBX-10652.

Accès API

Un grand nombre de sessions utilisateur ouvertes peuvent être créées lors de l'utilisation de scripts personnalisés avec la méthode user.login sans la présence du paramètre user.logout ensuite.

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 ZBX-11726 for more details.

Errors with fping execution in rootless containers

When containers are running in rootless mode or in a specific-restrictions environment, you may face errors related to fping execution when performing ICMP checks, such as fping: Operation not permitted or all packets to all resources lost.

To fix this problem add --cap-add=net_raw to "docker run" or "podman run" commands.

Additionally fping execution in non-root environments may require sysctl modification, i.e.:

sudo sysctl -w "net.ipv4.ping_group_range=0 1995"

where "1995" is the zabbix GID. For more details, see ZBX-22833.

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 ZBX-14318 more details.

SNMP traps

The "net-snmp-perl" package, needed for SNMP traps, has been removed in RHEL/CentOS 8.0-8.2; re-added in RHEL 8.3.

So if you are using RHEL 8.0-8.2, the best solution is to upgrade to RHEL 8.3; if you are using CentOS 8.0-8.2, you may wait for CentOS 8.3 or use a package from EPEL.

Please also see ZBX-17192 for more information.

Alerter process crash in Centos/RHEL 7

Instances of a Zabbix server alerter process crash have been encountered in Centos/RHEL 7. Please see ZBX-10461 for details.

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 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:

• ZBX-10911 (Problem with flipping frontend locales)
• ZBX-16297 (Problem with number processing in graphs using the bcdiv function of BC Math functions)

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 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 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 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 ZBX-10652.

Permission checks for dashboards with graphs

If SVG graphs are used in Zabbix dashboards, Zabbix frontend may generate non-optimized API queries when checking user permissions to hosts and items. This is happening because such searches support wildcards and case-insensitive name matching.

To improve performance of SQL statements, manually apply the patch index_host_and_item_name_upper_field.sql provided in Zabbix 5.0.31 and newer.

For MySQL, run:

shell> mysql -uzabbix -p<password> zabbix < index_host_and_item_name_upper_field.sql

For PostgreSQL, run:

shell> cat index_host_and_item_name_upper_field.sql | sudo -u zabbix psql zabbix

For Oracle, run:

sqlplus> @index_host_and_item_name_upper_field.sql

Creation of deterministic triggers should be enabled for the time of patch application. On MySQL and MariaDB, this requires GLOBAL log_bin_trust_function_creators = 1 to be set if binary logging is enabled and there is no superuser privileges and log_bin_trust_function_creators = 1 is not set in MySQL configuration file. To set the variable using MySQL console, run:

mysql> SET GLOBAL log_bin_trust_function_creators = 1;

Once the patch has been successfully applied, log_bin_trust_function_creators can be disabled:

mysql> SET GLOBAL log_bin_trust_function_creators = 0;

Triggers are also created for PostgreSQL and Oracle database.

Non-existing item value retrieval with MySQL 5.6/5.7

Zabbix server generates slow select queries in case of non-existing values for items. This is caused by a known 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 ZBX-10652.

Slow event info retrieval with older MySQL databases

Zabbix 5.0 installations with MySQL 5.X and 8.0.19 might run a slow query when retrieving problem/event information from the database. In particular, this affects the Problems by severity widget, event.get and problem.get API methods. To improve performance of SQL statements, apply the patch provided in ZBX-18080 (available for Zabbix 5.0.4 and newer).

API login

A large number of open user sessions can be created when using custom scripts with the 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 ZBX-14541.

Trimmed long IPv6 IP address in failed login information

Failed login attempt message will 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.

Zabbix agent checks on Windows

Non-existing DNS entries in a Server parameter of Zabbix agent configuration file (zabbix_agentd.conf) may increase Zabbix agent response time on Windows. This happens because Windows DNS caching daemon doesn't cache negative responses for IPv4 addresses. However, for IPv6 addresses negative responses are cached, so a possible workaround to this is disabling IPv4 on the host.

Setup wizard on SUSE with NGINX and php-fpm

Frontend setup wizard cannot save configuration file on SUSE with NGINX + php-fpm. This is caused by a setting in /usr/lib/systemd/system/php-fpm.service unit, which prevents Zabbix from writing to /etc. (introduced in PHP 7.4).

There are two workaround options available:

• Set the ProtectSystem option to 'true' instead of 'full' in the php-fpm systemd unit.
• Manually save /etc/zabbix/web/zabbix.conf.php file.

MySQL custom error codes

If Zabbix is used with MySQL installation on Azure, an unclear error message [9002] Some errors occurred may appear in Zabbix logs. This generic error text is sent to Zabbix server or proxy by the database. To get more information about the cause of the error, check Azure logs.