[comment]: # translation:outdated

[comment]: # ({49e33937-f843cd79})
# 6 Problemas conhecidos

[comment]: # ({/49e33937-f843cd79})

[comment]: # ({ed143cdd-e338613a})
#### Verificações IPMI

As verificações IPMI não irão funcionar com a biblioteca padrão do
Debian/Ubuntu. Para ajustar isso recompile a biblioteca OpenIPMI
habilitando o OpenSSL, conforme discutido em
[ZBX-6139](https://support.zabbix.com/browse/ZBX-6139).

[comment]: # ({/ed143cdd-e338613a})

[comment]: # ({ca7f142d-5c2a7ea7})
#### Verificações SSH

Algumas distribuições Linux como o Debian e Ubuntu não suportam chaves
privadas criptografadas (com frase) se a biblioteca libssh2 for
instalada a partir dos pacotes. Favor consultar
[ZBX-4850](https://support.zabbix.com/browse/ZBX-4850) para mais
detalhes.

[comment]: # ({/ca7f142d-5c2a7ea7})

[comment]: # ({7a4a2986-dfc40df7})
#### Verificações ODBC

O Zabbix Server ou Zabbix Proxy que utilizar o MySQL como seu banco de
dados poderá não funcionar corretamente com a biblioteca ODBC para MySQL
devido a um [BUG de envio de
dados](https://bugs.mysql.com/bug.php?id=73709). Favor consultar
[ZBX-7665](https://support.zabbix.com/browse/ZBX-7665) para mais
detalhes e alternativas disponíveis.

[comment]: # ({/7a4a2986-dfc40df7})

[comment]: # ({d2242c03-70c19e71})
#### Verificações HTTPS

Cenários web utilizando o protocolo HTTPS e as verificações de agente
`​net.tcp.service[https...]`​ e `​net.tcp.service.perf[https...]`​
poderão falhar se o servidor de destino estiver configurado para não
permitir o protocolo TLS em versão v1.0 ou anterior. ​ Consulte
[ZBX-9879](https://​support.zabbix.com/​browse/​ZBX-9879) para maiores
informações sobre alternativas disponíveis.

[comment]: # ({/d2242c03-70c19e71})

[comment]: # ({9e537cb5-3cf04fe3})
#### Gráficos

Modificações no horário de verão (DST) poderão resultar em
irregularidades ao apresentar as legendas do eixo X (duplicação de
datas, datas ausentes, etc).

[comment]: # ({/9e537cb5-3cf04fe3})

[comment]: # ({8c5cdd23-8c5cdd23})
#### 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
[ZBX-4850](https://support.zabbix.com/browse/ZBX-4850) for more details.

When using libssh 0.9.x on CentOS 8 with OpenSSH 8 SSH checks may
occasionally report "Cannot read data from SSH server". This is caused
by a libssh
[issue](https://gitlab.com/libssh/libssh-mirror/-/merge_requests/101)
([more detailed report](https://bugs.libssh.org/T231)). The error is
expected to have been fixed by a stable libssh 0.9.5 release. See also
[ZBX-17756](https://support.zabbix.com/browse/ZBX-17756) for details.

[comment]: # ({/8c5cdd23-8c5cdd23})

[comment]: # ({0c2fc2b9-0c2fc2b9})
#### ODBC checks

-   MySQL unixODBC driver should not be used with Zabbix server or
    Zabbix proxy compiled against MariaDB connector library and vice
    versa, if possible it is also better to avoid using the same
    connector as the driver due to an [upstream
    bug](https://bugs.mysql.com/bug.php?id=73709). Suggested setup:

```{=html}
<!-- -->
```
    PostgreSQL, SQLite or Oracle connector → MariaDB or MySQL unixODBC driver
    MariaDB connector → MariaDB unixODBC driver
    MySQL connector → MySQL unixODBC driver

Please see [ZBX-7665](https://support.zabbix.com/browse/ZBX-7665) for
more information and available workarounds.

-   XML data queried from Microsoft SQL Server may get truncated in
    various ways on Linux and UNIX systems.

```{=html}
<!-- -->
```
-   It has been observed that using ODBC checks on CentOS 8 for
    monitoring Oracle databases using Oracle Instant Client for Linux
    11.2.0.4.0 causes the Zabbix server to crash. The issue can be
    solved by upgrading Oracle Instant Client to 12.1.0.2.0, 12.2.0.1.0,
    18.5.0.0.0 or 19. See also
    [ZBX-18402](https://support.zabbix.com/browse/ZBX-18402).

[comment]: # ({/0c2fc2b9-0c2fc2b9})

[comment]: # ({1db730d3-1db730d3})
#### Incorrect request method parameter in items

The request method parameter, used only in HTTP checks, may be
incorrectly set to '1', a non-default value for all items as a result of
upgrade from a pre-4.0 Zabbix version. For details on how to fix this
situation, see [ZBX-19308](https://support.zabbix.com/browse/ZBX-19308).

[comment]: # ({/1db730d3-1db730d3})

[comment]: # ({4713dff4-4713dff4})
#### 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](https://bugzilla.redhat.com/show_bug.cgi?id=1057388) when "SSL
verify peer" is enabled in web scenarios or HTTP agent. Please see
[ZBX-10486](https://support.zabbix.com/browse/ZBX-10486) for more
information and available workarounds.

[comment]: # ({/4713dff4-4713dff4})

[comment]: # ({9cd7efe1-9cd7efe1})
#### 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](https://support.zabbix.com/browse/ZBX-11726) for more
details.

[comment]: # ({/9cd7efe1-9cd7efe1})

[comment]: # ({a4574c73-a4574c73})
#### 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.

[comment]: # ({/a4574c73-a4574c73})

[comment]: # ({d699f9d6-d699f9d6})
#### 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](https://support.zabbix.com/browse/ZBX-14318) more details.

[comment]: # ({/d699f9d6-d699f9d6})

[comment]: # ({7aeb682d-7aeb682d})
#### 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](https://support.zabbix.com/browse/ZBX-17192)
for more information.

[comment]: # ({/7aeb682d-7aeb682d})

[comment]: # ({f46cb486-f46cb486})
#### 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](https://support.zabbix.com/browse/ZBX-10461) for details.

[comment]: # ({/f46cb486-f46cb486})

[comment]: # ({8ffad918-8ffad918})
#### 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

[comment]: # ({/8ffad918-8ffad918})

[comment]: # ({6e1fb8fe-6e1fb8fe})
#### 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](https://www.php.net/manual/en/function.setlocale): 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](https://support.zabbix.com/browse/ZBX-10911) (Problem
    with flipping frontend locales)
-   [ZBX-16297](https://support.zabbix.com/browse/ZBX-16297) (Problem
    with number processing in graphs using the `bcdiv` function of BC
    Math functions)

[comment]: # ({/6e1fb8fe-6e1fb8fe})

[comment]: # ({4cf08f08-4cf08f08})
#### 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.

[comment]: # ({/4cf08f08-4cf08f08})

[comment]: # ({81fe18ae-81fe18ae})
#### 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](https://bugs.php.net/bug.php?id=78015). To work
around this, please set the "opcache.optimization\_level" parameter to
`0x7FFFBFDF` in the PHP configuration (php.ini file).

[comment]: # ({/81fe18ae-81fe18ae})

[comment]: # ({4f3b73ce-4f3b73ce})
#### Graphs

Changes to Daylight Saving Time (DST) result in irregularities when
displaying X axis labels (date duplication, date missing, etc).

[comment]: # ({/4f3b73ce-4f3b73ce})

[comment]: # ({357fdb5b-357fdb5b})
#### 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](https://support.zabbix.com/browse/ZBX-10884) for more
information).

[comment]: # ({/357fdb5b-357fdb5b})

[comment]: # ({82ff58c2-82ff58c2})
#### Slow MySQL queries

Zabbix server generates slow select queries in case of non-existing
values for items. This is caused by a known
[issue](https://bugs.mysql.com/bug.php?id=74602) 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](https://support.zabbix.com/browse/ZBX-10652).

[comment]: # ({/82ff58c2-82ff58c2})

[comment]: # ({4891543e-4891543e})
#### 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
[MDEV-19292](https://jira.mariadb.org/browse/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';

[comment]: # ({/4891543e-4891543e})

[comment]: # ({49733c6c-49733c6c})
#### API

The **output** parameter does not work properly with the `history.get`
method (fixed in 4.0.11).

[comment]: # ({/49733c6c-49733c6c})

[comment]: # ({b393528e-b393528e})
#### API login

A large number of open user sessions can be created when using custom
scripts with the `user.login` [method](/manual/api/reference/user/login)
without a following `user.logout`.

[comment]: # ({/b393528e-b393528e})

[comment]: # ({17c4463f-17c4463f})
#### 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](https://support.zabbix.com/browse/ZBX-14541).

[comment]: # ({/17c4463f-17c4463f})

[comment]: # ({42bcbe6d-42bcbe6d})
#### 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.

[comment]: # ({/42bcbe6d-42bcbe6d})

[comment]: # ({57420738-57420738})
#### 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.

[comment]: # ({/57420738-57420738})

[comment]: # ({1f99c5d8-1f99c5d8})
#### 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.

[comment]: # ({/1f99c5d8-1f99c5d8})

[comment]: # ({92e6eb3c-92e6eb3c})
#### 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.

[comment]: # ({/92e6eb3c-92e6eb3c})

[comment]: # ({f362564b-f362564b})
#### 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.

[comment]: # ({/f362564b-f362564b})

[comment]: # ({5f12232c-5f12232c})
#### Known issues in 4.0.0 - 4.0.2

-   If the *[Check now](/manual/config/items/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.

[comment]: # ({/5f12232c-5f12232c})

[comment]: # ({c24ab592-c24ab592})
#### 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

[comment]: # ({/c24ab592-c24ab592})

[comment]: # ({e793b2df-e793b2df})
#### 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.
-   [Negative problem
    duration](/manual/web_interface/frontend_sections/monitoring/problems#negative_problem_duration)
    affects the total result in [SLA calculation](/manual/it_services)
    or [Availability
    report](/manual/web_interface/frontend_sections/reports/availability),
    making it incorrect. Fixed in 4.0.4.

[comment]: # ({/e793b2df-e793b2df})

[comment]: # ({7faa28bd-7faa28bd})
#### 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.

[comment]: # ({/7faa28bd-7faa28bd})

[comment]: # ({ee68993e-ee68993e})
#### 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.

[comment]: # ({/ee68993e-ee68993e})

[comment]: # ({655f06ec-655f06ec})
#### Known issues in 4.0.0 - 4.0.5

-   `net.dns[]` Zabbix agent
    [item](/manual/config/items/itemtypes/zabbix_agent) does not support
    IPv6 addresses in its first parameter. Fixed in 4.0.6.

[comment]: # ({/655f06ec-655f06ec})

[comment]: # ({new-dc6e9c23})
##### Slow event info retrieval with older MySQL databases

Zabbix 4.0 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](https://support.zabbix.com/browse/ZBX-18080?focusedCommentId=477904&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-477904)
(available for Zabbix 4.0.26 and newer).

[comment]: # ({/new-dc6e9c23})

[comment]: # ({55cd59f6-55cd59f6})
#### 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.

[comment]: # ({/55cd59f6-55cd59f6})

[comment]: # ({1f7fbf82-1f7fbf82})
#### 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
    [ZBX-16180](https://support.zabbix.com/browse/ZBX-16180) for
    details). As a result, this requirement is rolled back in 4.0.9.

[comment]: # ({/1f7fbf82-1f7fbf82})

[comment]: # ({2eaffe5e-2eaffe5e})
#### 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 [ZBX-9084](https://support.zabbix.com/browse/ZBX-9084) for
    more details.

[comment]: # ({/2eaffe5e-2eaffe5e})