Check environment configurations

This topic lists all environment and system configuration items that you must check and set before deploying StarRocks. Setting these configuration items properly allows your StarRocks cluster to work with high availability and performance.

Ports

StarRocks uses specific ports for different services. Check whether these ports are occupied on each instance if you have deployed other services on these instances.

FE ports

On the instances used for the FE deployment, you need to check the following ports:

• 8030: FE HTTP server port (http_port)
• 9020: FE Thrift server port (rpc_port)
• 9030: FE MySQL server port (query_port)
• 9010: FE internal communication port (edit_log_port)

Run the following commands on the FE instances to check whether these ports are occupied:

netstat -tunlp | grep 8030
netstat -tunlp | grep 9020
netstat -tunlp | grep 9030
netstat -tunlp | grep 9010

If any of the above ports are occupied, you must find alternatives and specify them later when you deploy FE nodes. For detailed instructions, see Deploy StarRocks - Start the FE service.

BE ports

On the instances used for the BE deployment, you need to check the following ports:

• 9060: BE Thrift server port (be_port)
• 8040: BE HTTP server port (be_http_port)
• 9050: BE heartbeat service port (heartbeat_service_port)
• 8060: BE BRPC port (brpc_port)

Run the following commands on the BE instances to check whether these ports are occupied:

netstat -tunlp | grep 9060
netstat -tunlp | grep 8040
netstat -tunlp | grep 9050
netstat -tunlp | grep 8060

If any of the above ports are occupied, you must find alternatives and specify them later when you deploy BE nodes. For detailed instructions, see Deploy StarRocks - Start the BE service.

CN ports

On the instances used for the CN deployment, you need to check the following ports:

• 9060: CN Thrift server port (thrift_port)
• 8040: CN HTTP server port (be_http_port)
• 9050: CN heartbeat service port (heartbeat_service_port)
• 8060: CN BRPC port (brpc_port)

Run the following commands on the CN instances to check whether these ports are occupied:

netstat -tunlp | grep 9060
netstat -tunlp | grep 8040
netstat -tunlp | grep 9050
netstat -tunlp | grep 8060

If any of the above ports are occupied, you must find alternatives and specify them later when you deploy CN nodes. For detailed instructions, see Deploy StarRocks - Start the CN service.

Hostnames

If you want to enable FQDN access for your StarRocks cluster, you must assign a hostname to each instance.

In the file /etc/hosts on each instance, you must specify the IP addresses and corresponding hostnames of all the other instances in the cluster.

CAUTION

All IP addresses in the file /etc/hosts must be unique.

JDK configuration

StarRocks relies on the environment variable JAVA_HOME to locate the Java dependency on the instance.

Run the following command to check the environment variable JAVA_HOME:

echo $JAVA_HOME

Follow these steps to set JAVA_HOME:

1. Set JAVA_HOME in the file /etc/profile:

   sudo vi /etc/profile
   # Replace <path_to_JDK> with the path where JDK is installed.
   export JAVA_HOME=<path_to_JDK>
   export PATH=$PATH:$JAVA_HOME/bin

2. Bring the change into effect:

   source /etc/profile

Run the following command to verify the change:

java -version

CPU scaling governor

This configuration item is optional. You can skip it if your CPU does not support the scaling governor.

The CPU scaling governor controls the CPU power mode. If your CPU supports it, we recommend you set it to performance for better CPU performance:

echo 'performance' | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

Memory configurations

Memory Overcommit

Memory Overcommit allows the operating system to overcommit memory resources to processes. We recommend you enable Memory Overcommit.

echo 1 | sudo tee /proc/sys/vm/overcommit_memory

Transparent Huge Pages

Transparent Huge Pages are enabled by default. We recommend you disable this feature because it can interfere with the memory allocator, and thereby lead to a drop in performance.

echo 'madvise' | sudo tee /sys/kernel/mm/transparent_hugepage/enabled

Swap Space

We recommend you disable Swap Space.

Follow these steps to check and disable Swap Space:

1. Disable Swap Space.

   swapoff /<path_to_swap_space>

2. Delete the Swap Space information from the configuration file /etc/fstab.

   /<path_to_swap_space> swap swap defaults 0 0

3. Verify that Swap Space is disabled.

   free -m

Swappiness

We recommend you disable swappiness to eliminate its impact on performance.

echo 0 | sudo tee /proc/sys/vm/swappiness

Storage configurations

We recommend that you choose your suitable scheduler algorithm in accordance with the storage medium you use.

You can run the following command to check the scheduler algorithm that you are using:

cat /sys/block/${disk}/queue/scheduler
# For example, run cat /sys/block/vdb/queue/scheduler

We recommend you use the mq-deadline scheduler for SATA disks and the kyber scheduler algorithm for SSD and NVMe disks.

SATA

The mq-deadline scheduler algorithm suits SATA disks.

Modify this item temporarily:

echo mq-deadline | sudo tee /sys/block/${disk}/queue/scheduler

To make the change permanent, run the following command after you modify this item:

chmod +x /etc/rc.d/rc.local

SSD and NVMe

The kyber scheduler algorithm suits NVMe or SSD disks.

Modify this item temporarily:

echo kyber | sudo tee /sys/block/${disk}/queue/scheduler

If your system does not support the kyber scheduler for SSD and NVMe, we recommend you use the none (or noop) scheduler.

echo none | sudo tee /sys/block/${disk}/queue/scheduler

To make the change permanent, run the following command after you modify this item:

chmod +x /etc/rc.d/rc.local

SELinux

We recommend you disable SELinux.

sed -i 's/SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
sed -i 's/SELINUXTYPE/#SELINUXTYPE/' /etc/selinux/config
setenforce 0 

Firewall

Open the internal ports for FE nodes, BE nodes, and Broker if your firewall is enabled.

systemctl stop firewalld.service
systemctl disable firewalld.service

LANG variable

Run the following command to check and configure the LANG variable manually:

echo "export LANG=en_US.UTF8" >> /etc/profile
source /etc/profile

Time zone

Set this item in accordance with your actual time zone.

The following example sets the time zone to /Asia/Shanghai.

cp -f /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
hwclock

ulimit configurations

Problems can occur with StarRocks if the values of max file descriptors and max user processes are abnormally small.

Max file descriptors

You can set the maximum number of file descriptors by running the following command:

ulimit -n 65535

Max user processes

You can set the maximum number of user processes by running the following command:

ulimit -u 40960

File system configuration

We recommend you use the ext4 or xfs journaling file system. You can run the following command to check the mount type:

df -Th

Network configuration

tcp_abort_on_overflow

Allow the system to reset new connections if the system is currently overflowed with new connection attempts that the daemon(s) can not handle:

echo 1 | sudo tee /proc/sys/net/ipv4/tcp_abort_on_overflow

somaxconn

Specify the maximum number of connection requests queued for any listening socket to 1024:

echo 1024 | sudo tee /proc/sys/net/core/somaxconn

NTP configuration

You must configure time synchronization between nodes within your StarRocks cluster to ensure linear consistency of transactions. You can either use the internet time service provided by pool.ntp.org, or use the NTP service built in an offline environment. For example, you can use the NTP service provided by your cloud service provider.

1. Check if the NTP time server exists.

   rpm -qa | grep ntp

2. Install the NTP service if there is not one.

   sudo yum install ntp ntpdate && \
   sudo systemctl start ntpd.service && \
   sudo systemctl enable ntpd.service

3. Check the NTP service.

   systemctl list-unit-files | grep ntp

4. Check the connectivity and monitoring status of the NTP service.

   netstat -tlunp | grep ntp

5. Check if your application is synchronized with the NTP server.

   ntpstat

6. Check the state of all the configured NTP servers in your network.

   ntpq -p

High concurrency configurations

If your StarRocks cluster has a high load concurrency, we recommend you set the following configurations:

echo 120000 > /proc/sys/kernel/threads-max
echo 262144 > /proc/sys/vm/max_map_count
echo 200000 > /proc/sys/kernel/pid_max