Configuration Guide
Overview of Node Manager Configuration
Node Manager configuration involves setting parameters that control resource allocation, container management, and cluster performance. Proper configuration ensures optimal utilization of cluster resources.
Key Configuration Files
1. yarn-site.xml
The primary configuration file for YARN settings, located at /etc/hadoop/conf/yarn-site.xml
.
<configuration>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>16384</value>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>8</value>
</property>
</configuration>
Configuration Parameters
Parameter |
Description |
Default Value |
yarn.nodemanager.resource.memory-mb |
Total RAM available for containers |
System dependent |
yarn.nodemanager.resource.cpu-vcores |
Number of CPU cores available |
System dependent |
yarn.nodemanager.local-dirs |
Directories for local file storage |
/tmp/hadoop-yarn/node-local-dir |
Resource Allocation Strategy
graph TD
A[Node Manager] -->|Evaluate Resources| B{Available Memory}
A -->|Check| C{Available CPU}
B -->|Allocate| D[Container Resources]
C -->|Distribute| D
Advanced Configuration Techniques
1. Memory Configuration
## Calculate total memory
total_memory=$(free -m | awk '/^Mem:/{print $2}')
reserved_memory=$((total_memory * 20 / 100))
available_memory=$((total_memory - reserved_memory))
## Set in yarn-site.xml
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>$available_memory</value>
</property>
2. CPU Configuration
## Determine available CPU cores
total_cores=$(nproc)
reserved_cores=$((total_cores / 4))
available_cores=$((total_cores - reserved_cores))
## Set in yarn-site.xml
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>$available_cores</value>
</property>
Container Management Settings
<property>
<name>yarn.nodemanager.container-executor.class</name>
<value>org.apache.hadoop.yarn.server.nodemanager.DefaultContainerExecutor</value>
</property>
Logging and Monitoring Configuration
<property>
<name>yarn.nodemanager.log-dirs</name>
<value>/var/log/hadoop-yarn/containers</value>
</property>
Best Practices
- Always leave system resources for OS operations
- Match configuration with actual hardware capabilities
- Regularly monitor and adjust configurations
Verification Commands
## Check YARN configuration
yarn nodemanager -format
yarn nodemanager -status
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