mirror of
https://github.com/apache/impala.git
synced 2025-12-19 09:58:28 -05:00
955868f88a
-Added broadcast_bytes_limit query option Change-Id: I4385749de35f8379ecf6566fe515ed500b42d6cc Reviewed-on: http://gerrit.cloudera.org:8080/14863 Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Reviewed-by: Joe McDonnell <joemcdonnell@cloudera.com>
909 lines
27 KiB
XML
909 lines
27 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!--
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Licensed to the Apache Software Foundation (ASF) under one
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or more contributor license agreements. See the NOTICE file
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distributed with this work for additional information
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regarding copyright ownership. The ASF licenses this file
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to you under the Apache License, Version 2.0 (the
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"License"); you may not use this file except in compliance
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with the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing,
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software distributed under the License is distributed on an
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"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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KIND, either express or implied. See the License for the
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specific language governing permissions and limitations
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under the License.
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-->
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
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<concept rev="ver" id="known_issues">
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<title><ph audience="standalone">Known Issues and Workarounds in Impala</ph><ph audience="integrated">Apache Impala Known Issues</ph></title>
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<prolog>
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<metadata>
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<data name="Category" value="Impala"/>
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<data name="Category" value="Release Notes"/>
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<data name="Category" value="Known Issues"/>
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<data name="Category" value="Troubleshooting"/>
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<data name="Category" value="Upgrading"/>
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<data name="Category" value="Administrators"/>
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<data name="Category" value="Developers"/>
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<data name="Category" value="Data Analysts"/>
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</metadata>
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</prolog>
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<conbody>
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<p>
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The following sections describe known issues and workarounds in Impala, as of the current
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production release. This page summarizes the most serious or frequently encountered issues
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in the current release, to help you make planning decisions about installing and
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upgrading. Any workarounds are listed here. The bug links take you to the Impala issues
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site, where you can see the diagnosis and whether a fix is in the pipeline.
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</p>
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<note>
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The online issue tracking system for Impala contains comprehensive information and is
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updated in real time. To verify whether an issue you are experiencing has already been
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reported, or which release an issue is fixed in, search on the
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<xref href="https://issues.apache.org/jira/" scope="external" format="html">issues.apache.org
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JIRA tracker</xref>.
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</note>
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<p outputclass="toc inpage"/>
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<p>
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For issues fixed in various Impala releases, see
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<xref href="impala_fixed_issues.xml#fixed_issues"/>.
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</p>
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<!-- Use as a template for new issues.
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<concept id="">
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<title></title>
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<conbody>
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<p>
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</p>
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<p><b>Apache Issue:</b> <xref keyref=""></xref></p>
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<p><b>Severity:</b> High</p>
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<p><b>Resolution:</b> </p>
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<p><b>Workaround:</b> </p>
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</conbody>
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</concept>
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-->
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</conbody>
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<concept id="known_issues_startup">
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<title>Impala Known Issues: Startup</title>
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<conbody>
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<p>
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These issues can prevent one or more Impala-related daemons from starting properly.
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</p>
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</conbody>
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<concept id="IMPALA-4978">
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<title>Impala requires FQDN from hostname command on Kerberized clusters</title>
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<conbody>
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<p>
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The method Impala uses to retrieve the host name while constructing the Kerberos
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principal is the <codeph>gethostname()</codeph> system call. This function might not
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always return the fully qualified domain name, depending on the network configuration.
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If the daemons cannot determine the FQDN, Impala does not start on a Kerberized
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cluster.
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</p>
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<p>
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<b>Workaround:</b> Test if a host is affected by checking whether the output of the
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<cmdname>hostname</cmdname> command includes the FQDN. On hosts where
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<cmdname>hostname</cmdname>, only returns the short name, pass the command-line flag
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<codeph>‑‑hostname=<varname>fully_qualified_domain_name</varname></codeph>
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in the startup options of all Impala-related daemons.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-4978">IMPALA-4978</xref>
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</p>
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</conbody>
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</concept>
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</concept>
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<concept id="known_issues_performance">
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<title id="ki_performance">Impala Known Issues: Performance</title>
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<conbody>
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<p>
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These issues involve the performance of operations such as queries or DDL statements.
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</p>
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</conbody>
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<concept id="impala-6671">
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<title>Metadata operations block read-only operations on unrelated tables</title>
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<conbody>
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<p>
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Metadata operations that change the state of a table, like <codeph>COMPUTE
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STATS</codeph> or <codeph>ALTER RECOVER PARTITIONS</codeph>, may delay metadata
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propagation of unrelated unloaded tables triggered by statements like
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<codeph>DESCRIBE</codeph> or <codeph>SELECT</codeph> queries.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-6671">IMPALA-6671</xref>
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</p>
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</conbody>
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</concept>
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</concept>
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<!--<concept id="known_issues_usability"><title id="ki_usability">Impala Known Issues: Usability</title><conbody><p> These issues affect the convenience of interacting directly with Impala, typically through the Impala shell or Hue. </p></conbody></concept>-->
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<concept id="known_issues_drivers">
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<title id="ki_drivers">Impala Known Issues: JDBC and ODBC Drivers</title>
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<conbody>
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<p>
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These issues affect applications that use the JDBC or ODBC APIs, such as business
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intelligence tools or custom-written applications in languages such as Java or C++.
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</p>
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</conbody>
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<concept id="IMPALA-1792" rev="IMPALA-1792">
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<title>ImpalaODBC: Can not get the value in the SQLGetData(m-x th column) after the SQLBindCol(m th column)</title>
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<conbody>
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<p>
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If the ODBC <codeph>SQLGetData</codeph> is called on a series of columns, the function
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calls must follow the same order as the columns. For example, if data is fetched from
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column 2 then column 1, the <codeph>SQLGetData</codeph> call for column 1 returns
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<codeph>NULL</codeph>.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-1792">IMPALA-1792</xref>
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</p>
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<p>
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<b>Workaround:</b> Fetch columns in the same order they are defined in the table.
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</p>
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</conbody>
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</concept>
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</concept>
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<concept id="known_issues_security">
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<title id="ki_security">Impala Known Issues: Security</title>
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<conbody>
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<p>
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These issues are related to security features, such as Kerberos authentication, Sentry
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authorization, encryption, auditing, and redaction.
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</p>
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</conbody>
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<concept id="impala-7072">
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<title>Impala does not support Heimdal Kerberos</title>
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<conbody>
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<p>
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Heimdal Kerberos is not supported in Impala.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-7072">IMPALA-7072</xref>
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</p>
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<p>
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<b>Affected Versions:</b> All versions of Impala
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</p>
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</conbody>
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</concept>
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<concept id="id_p1n_tbx_22b">
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<title>Impala does not allow the use of insecure clusters with public IPs</title>
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<conbody>
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<p>
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Starting in <keyword keyref="impala212_full"/>, Impala, by default, will only allow
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unencrypted or unauthenticated connections from trusted subnets:
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<codeph>127.0.0.0/8</codeph>, <codeph>10.0.0.0/8</codeph>,
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<codeph>172.16.0.0/12</codeph>, <codeph>192.168.0.0/16</codeph>,
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<codeph>169.254.0.0/16</codeph>. Unencrypted or unauthenticated connections from
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publicly routable IPs will be rejected.
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</p>
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<p>
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The trusted subnets can be configured using the <codeph>--trusted_subnets</codeph>
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flag. Set it to '<codeph>0.0.0.0/0</codeph>' to allow unauthenticated connections from
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all remote IP addresses. However, if network access is not otherwise restricted by a
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firewall, malicious users may be able to gain unauthorized access.
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</p>
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</conbody>
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</concept>
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</concept>
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<concept id="known_issues_resources">
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<title id="ki_resources">Impala Known Issues: Resources</title>
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<conbody>
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<p>
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These issues involve memory or disk usage, including out-of-memory conditions, the
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spill-to-disk feature, and resource management features.
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</p>
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</conbody>
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<concept id="IMPALA-5605">
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<title>Configuration to prevent crashes caused by thread resource limits</title>
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<conbody>
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<p>
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Impala could encounter a serious error due to resource usage under very high
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concurrency. The error message is similar to:
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</p>
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<codeblock><![CDATA[
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F0629 08:20:02.956413 29088 llvm-codegen.cc:111] LLVM hit fatal error: Unable to allocate section memory!
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terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::thread_resource_error> >'
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]]>
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</codeblock>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-5605">IMPALA-5605</xref>
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</p>
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<p>
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<b>Severity:</b> High
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</p>
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<p>
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<b>Workaround:</b> To prevent such errors, configure each host running an
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<cmdname>impalad</cmdname> daemon with the following settings:
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</p>
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<codeblock>
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echo 2000000 > /proc/sys/kernel/threads-max
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echo 2000000 > /proc/sys/kernel/pid_max
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echo 8000000 > /proc/sys/vm/max_map_count
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</codeblock>
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<p>
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Add the following lines in <filepath>/etc/security/limits.conf</filepath>:
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</p>
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<codeblock>
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impala soft nproc 262144
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impala hard nproc 262144
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</codeblock>
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</conbody>
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</concept>
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<concept id="drop_table_purge_s3a">
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<title><b>Breakpad minidumps can be very large when the thread count is high</b></title>
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<conbody>
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<p>
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The size of the breakpad minidump files grows linearly with the number of threads. By
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default, each thread adds 8 KB to the minidump size. Minidump files could consume
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significant disk space when the daemons have a high number of threads.
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</p>
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<p>
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<b>Workaround:</b> Add
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<systemoutput>--minidump_size_limit_hint_kb=size</systemoutput>
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to set a soft upper limit on the size of each minidump file. If the minidump file
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would exceed that limit, Impala reduces the amount of information for each thread from
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8 KB to 2 KB. (Full thread information is captured for the first 20 threads, then 2 KB
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per thread after that.) The minidump file can still grow larger than the "hinted"
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size. For example, if you have 10,000 threads, the minidump file can be more than 20
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MB.
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</p>
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<p>
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<b>Apache Issue:</b>
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<xref href="https://issues.cloudera.org/browse/IMPALA-3509"
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format="html" scope="external">IMPALA-3509</xref>
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</p>
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</conbody>
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</concept>
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<concept id="IMPALA-691">
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<title><b>Process mem limit does not account for the JVM's memory usage</b></title>
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<conbody>
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<p>
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Some memory allocated by the JVM used internally by Impala is not counted against the
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memory limit for the impalad daemon.
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</p>
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<p>
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<b>Workaround:</b> To monitor overall memory usage, use the top command, or add the
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memory figures in the Impala web UI <b>/memz</b> tab to JVM memory usage shown on the
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<b>/metrics</b> tab.
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</p>
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<p>
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<b>Apache Issue:</b>
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<xref href="https://issues.cloudera.org/browse/IMPALA-691"
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format="html" scope="external">IMPALA-691</xref>
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</p>
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</conbody>
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</concept>
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</concept>
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<concept id="known_issues_correctness">
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<title id="ki_correctness">Impala Known Issues: Correctness</title>
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<conbody>
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<p>
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These issues can cause incorrect or unexpected results from queries. They typically only
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arise in very specific circumstances.
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</p>
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</conbody>
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<concept id="IMPALA-3094" rev="IMPALA-3094">
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<title>Incorrect result due to constant evaluation in query with outer join</title>
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<conbody>
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<p>
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An <codeph>OUTER JOIN</codeph> query could omit some expected result rows due to a
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constant such as <codeph>FALSE</codeph> in another join clause. For example:
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</p>
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<codeblock><![CDATA[
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explain SELECT 1 FROM alltypestiny a1
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INNER JOIN alltypesagg a2 ON a1.smallint_col = a2.year AND false
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RIGHT JOIN alltypes a3 ON a1.year = a1.bigint_col;
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+---------------------------------------------------------+
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| Explain String |
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+---------------------------------------------------------+
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| Estimated Per-Host Requirements: Memory=1.00KB VCores=1 |
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| |
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| 00:EMPTYSET |
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+---------------------------------------------------------+
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]]>
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</codeblock>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-3094">IMPALA-3094</xref>
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</p>
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<p>
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<b>Severity:</b> High
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</p>
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</conbody>
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</concept>
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<concept id="IMPALA-2422" rev="IMPALA-2422">
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<title>% escaping does not work correctly when occurs at the end in a LIKE clause</title>
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<conbody>
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<p>
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If the final character in the RHS argument of a <codeph>LIKE</codeph> operator is an
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escaped <codeph>\%</codeph> character, it does not match a <codeph>%</codeph> final
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character of the LHS argument.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-2422">IMPALA-2422</xref>
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</p>
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</conbody>
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</concept>
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<concept id="IMPALA-2603" rev="IMPALA-2603">
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<title>Crash: impala::Coordinator::ValidateCollectionSlots</title>
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<conbody>
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<p>
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A query could encounter a serious error if includes multiple nested levels of
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<codeph>INNER JOIN</codeph> clauses involving subqueries.
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</p>
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<p>
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<b>Apache Issue:</b> <xref keyref="IMPALA-2603">IMPALA-2603</xref>
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</p>
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</conbody>
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</concept>
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</concept>
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<!--<concept id="known_issues_metadata"><title id="ki_metadata">Impala Known Issues: Metadata</title><conbody><p> These issues affect how Impala interacts with metadata. They cover areas such as the metastore database, the <codeph>COMPUTE STATS</codeph> statement, and the Impala <cmdname>catalogd</cmdname> daemon. </p></conbody></concept>-->
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<concept id="known_issues_interop">
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<title id="ki_interop">Impala Known Issues: Interoperability</title>
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<conbody>
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<p>
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These issues affect the ability to interchange data between Impala and other database
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systems. They cover areas such as data types and file formats.
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</p>
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</conbody>
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<concept id="hadoop-15720">
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<title>Queries Stuck on Failed HDFS Calls and not Timing out</title>
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<conbody>
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<p> In Impala 3.2 and higher, if the following error appears multiple
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times in a short duration while running a query, it would mean that
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the connection between the <codeph>impalad</codeph> and the HDFS
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NameNode is in a bad state and hence the <codeph>impalad</codeph>
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would have to be restarted: </p>
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<codeblock>"hdfsOpenFile() for <filename> at backend <hostname:port> failed to finish before the <hdfs_operation_timeout_sec> second timeout " </codeblock>
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<p>In Impala 3.1 and lower, the same issue would cause Impala to wait for
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a long time or hang without showing the above error message.</p>
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<p>
|
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<b>Apache Issue:</b>
|
|
<xref href="https://issues.apache.org/jira/browse/HADOOP-15720"
|
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format="html" scope="external">HADOOP-15720</xref>
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</p>
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<p>
|
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<b>Affected Versions:</b> All versions of Impala
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</p>
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<p>
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<b>Workaround:</b> Restart the <codeph>impalad</codeph> in the bad state.
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</p>
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</conbody>
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</concept>
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<concept id="describe_formatted_avro">
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<title>DESCRIBE FORMATTED gives error on Avro table</title>
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|
|
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<conbody>
|
|
|
|
<p>
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This issue can occur either on old Avro tables (created prior to Hive 1.1) or when
|
|
changing the Avro schema file by adding or removing columns. Columns added to the
|
|
schema file will not show up in the output of the <codeph>DESCRIBE FORMATTED</codeph>
|
|
command. Removing columns from the schema file will trigger a
|
|
<codeph>NullPointerException</codeph>.
|
|
</p>
|
|
|
|
<p>
|
|
As a workaround, you can use the output of <codeph>SHOW CREATE TABLE</codeph> to drop
|
|
and recreate the table. This will populate the Hive metastore database with the
|
|
correct column definitions.
|
|
</p>
|
|
|
|
<note type="warning">
|
|
<p>
|
|
Only use this for external tables, or Impala will remove the data files. In case of
|
|
an internal table, set it to external first:
|
|
<codeblock>
|
|
ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
|
|
</codeblock>
|
|
(The part in parentheses is case sensitive.) Make sure to pick the right choice
|
|
between internal and external when recreating the table. See
|
|
<xref href="impala_tables.xml#tables"/> for the differences between internal and
|
|
external tables.
|
|
</p>
|
|
</note>
|
|
|
|
<p>
|
|
<b>Severity:</b> High
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="flume_writeformat_text">
|
|
|
|
<title>Configuration needed for Flume to be compatible with Impala</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
For compatibility with Impala, the value for the Flume HDFS Sink
|
|
<codeph>hdfs.writeFormat</codeph> must be set to <codeph>Text</codeph>, rather than
|
|
its default value of <codeph>Writable</codeph>. The <codeph>hdfs.writeFormat</codeph>
|
|
setting must be changed to <codeph>Text</codeph> before creating data files with
|
|
Flume; otherwise, those files cannot be read by either Impala or Hive.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Resolution:</b> This information has been requested to be added to the upstream
|
|
Flume documentation.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-635" rev="IMPALA-635">
|
|
|
|
<title>Avro Scanner fails to parse some schemas</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
The default value in Avro schema must match type of first union type, e.g. if the
|
|
default value is <codeph>null</codeph>, then the first type in the
|
|
<codeph>UNION</codeph> must be <codeph>"null"</codeph>.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-635">IMPALA-635</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b>Swap the order of the fields in the schema specification. For
|
|
example, use <codeph>["null", "string"]</codeph> instead of <codeph>["string",
|
|
"null"]</codeph>. Note that the files written with the problematic schema must be
|
|
rewritten with the new schema because Avro files have embedded schemas.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-1024" rev="IMPALA-1024">
|
|
|
|
<title>Impala BE cannot parse Avro schema that contains a trailing semi-colon</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
If an Avro table has a schema definition with a trailing semicolon, Impala encounters
|
|
an error when the table is queried.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-1024">IMPALA-1024</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Severity:</b> Remove trailing semicolon from the Avro schema.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-1652" rev="IMPALA-1652">
|
|
|
|
<title>Incorrect results with basic predicate on CHAR typed column</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
When comparing a <codeph>CHAR</codeph> column value to a string literal, the literal
|
|
value is not blank-padded and so the comparison might fail when it should match.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-1652">IMPALA-1652</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Use the <codeph>RPAD()</codeph> function to blank-pad literals
|
|
compared with <codeph>CHAR</codeph> columns to the expected length.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
<concept id="IMPALA-8953">
|
|
<title>Tables and databases sharing same name can cause query
|
|
failures</title>
|
|
<conbody>
|
|
<p>A table and a database that share the same name can cause a query
|
|
failure if the table is not readable by Impala, for example, the table
|
|
was created in Hive in the Open CSV Serde format. The following
|
|
exception will return:</p>
|
|
<codeblock>CAUSED BY: TableLoadingException: Unrecognized table type for table</codeblock>
|
|
<p>
|
|
<b>Apache Issue:</b>
|
|
<xref keyref="IMPALA-8953">IMPALA-8953</xref>
|
|
</p>
|
|
<p>
|
|
<b>Workaround:</b> Do not create databases and tables with the same
|
|
names.</p>
|
|
</conbody>
|
|
</concept>
|
|
|
|
</concept>
|
|
|
|
<concept id="known_issues_limitations">
|
|
|
|
<title>Impala Known Issues: Limitations</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
These issues are current limitations of Impala that require evaluation as you plan how
|
|
to integrate Impala into your data management workflow.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
<concept id="IMPALA-4551">
|
|
|
|
<title>Set limits on size of expression trees</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
Very deeply nested expressions within queries can exceed internal Impala limits,
|
|
leading to excessive memory usage.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-4551">IMPALA-4551</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Severity:</b> High
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Avoid queries with extremely large expression trees. Setting the
|
|
query option <codeph>disable_codegen=true</codeph> may reduce the impact, at a cost of
|
|
longer query runtime.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-77" rev="IMPALA-77">
|
|
|
|
<title>Impala does not support running on clusters with federated namespaces</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
Impala does not support running on clusters with federated namespaces. The
|
|
<codeph>impalad</codeph> process will not start on a node running such a filesystem
|
|
based on the <codeph>org.apache.hadoop.fs.viewfs.ViewFs</codeph> class.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-77">IMPALA-77</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Anticipated Resolution:</b> Limitation
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Use standard HDFS on all Impala nodes.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
</concept>
|
|
|
|
<concept id="known_issues_misc">
|
|
|
|
<title>Impala Known Issues: Miscellaneous</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
These issues do not fall into one of the above categories or have not been categorized
|
|
yet.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
<concept id="IMPALA-2005" rev="IMPALA-2005">
|
|
|
|
<title>A failed CTAS does not drop the table if the insert fails</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
If a <codeph>CREATE TABLE AS SELECT</codeph> operation successfully creates the target
|
|
table but an error occurs while querying the source table or copying the data, the new
|
|
table is left behind rather than being dropped.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-2005">IMPALA-2005</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Drop the new table manually after a failed <codeph>CREATE TABLE AS
|
|
SELECT</codeph>.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-1821" rev="IMPALA-1821">
|
|
|
|
<title>Casting scenarios with invalid/inconsistent results</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
Using a <codeph>CAST()</codeph> function to convert large literal values to smaller
|
|
types, or to convert special values such as <codeph>NaN</codeph> or
|
|
<codeph>Inf</codeph>, produces values not consistent with other database systems. This
|
|
could lead to unexpected results from queries.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-1821">IMPALA-1821</xref>
|
|
</p>
|
|
|
|
<!-- <p><b>Workaround:</b> Doublecheck that <codeph>CAST()</codeph> operations work as expect. The issue applies to expressions involving literals, not values read from table columns.</p> -->
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMPALA-532" rev="IMPALA-532">
|
|
|
|
<title>Impala should tolerate bad locale settings</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
If the <codeph>LC_*</codeph> environment variables specify an unsupported locale,
|
|
Impala does not start.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-532">IMPALA-532</xref>
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Add <codeph>LC_ALL="C"</codeph> to the environment settings for
|
|
both the Impala daemon and the Statestore daemon. See
|
|
<xref href="impala_config_options.xml#config_options"/> for details about modifying
|
|
these environment settings.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Resolution:</b> Fixing this issue would require an upgrade to Boost 1.47 in the
|
|
Impala distribution.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
<concept id="IMP-1203">
|
|
|
|
<title>Log Level 3 Not Recommended for Impala</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
The extensive logging produced by log level 3 can cause serious performance overhead
|
|
and capacity issues.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Workaround:</b> Reduce the log level to its default value of 1, that is,
|
|
<codeph>GLOG_v=1</codeph>. See <xref href="impala_logging.xml#log_levels"/> for
|
|
details about the effects of setting different logging levels.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
</concept>
|
|
|
|
<concept id="known_issues_crash">
|
|
|
|
<title>Impala Known Issues: Crashes and Hangs</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
These issues can cause Impala to quit or become unresponsive.
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
<concept id="impala-6841">
|
|
|
|
<title>Unable to view large catalog objects in catalogd Web UI</title>
|
|
|
|
<conbody>
|
|
|
|
<p>
|
|
In <codeph>catalogd</codeph> Web UI, you can list metadata objects and view their
|
|
details. These details are accessed via a link and printed to a string formatted using
|
|
thrift's <codeph>DebugProtocol</codeph>. Printing large objects (> 1 GB) in Web UI can
|
|
crash <codeph>catalogd</codeph>.
|
|
</p>
|
|
|
|
<p>
|
|
<b>Apache Issue:</b> <xref keyref="IMPALA-6841">IMPALA-6841</xref>
|
|
</p>
|
|
|
|
</conbody>
|
|
|
|
</concept>
|
|
|
|
</concept>
|
|
|
|
</concept>
|