Problem Description
rsync: command not found rsync: connection unexpectedly closed (0 bytes received so far) [sender] rsync error: remote command not found (code 127) at io.c(226) [sender=3.1.2]
Cause
of the problem This problem occurs because not only does the synchronizing machine need to have rsync installed, but it also needs to be installed on the machine being synchronized.
Solution
Install it in both the synchronizing machine and the synchronizing machinersync
yum -y install rsync
hadoop start error:
Starting namenodes on [733ec62951d5]
733ec62951d5: ERROR: Cannot set priority of namenode process 868
Starting datanodes
localhost: ERROR: Cannot set priority of datanode process 974
2022-01-15 13:56:41,689 ERROR conf.Configuration: error parsing conf core-site.xml
It was noticed that it was caused by an error in the core-site.xml configuration file. After modification, the correct core-site.xml configuration file is as follows.
?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!--
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. See accompanying LICENSE file.
-->
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://172.17.0.3:9000</value>
</property>
</configuration>
Correct HDFS site The XML configuration file is as follows:
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!--
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. See accompanying LICENSE file.
-->
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>