Based on the long-term stable Linux Kernel version 4.14.105, TencentOS Server introduces new features applicable to cloud scenarios and improves the kernel performance and resolves major defects.
Performance Optimizations for Container Scenarios
TencentOS Server optimizes container scenarios by providing enhanced isolation and optimized performance:
- meminfo, vmstat, cpuinfo, stat, and loadavg isolation.
- Sysctl isolation, such as tcp_no_delay_ack, tcp_max_orphans.
- Fixes bugs in file systems and networks.
- Fixes exceptions caused by reuse of connections in high-concurrence scenarios in IPVS mode.
- Fixes network glitches caused by excessive IPVS rules under high-spec nodes (with a large number of CPU cores) in IPVS mode.
- Fixes network glitches caused when cAdvisor got stuck in the kernel state for too long while reading memcg in high-density container scenarios (a large number of containers on a single node).
- Fixes network glitches caused by CPU load balancing in scenarios of high-spec nodes (with a large number of CPU cores) and large pods (occupying many cores with high usage per core).
- Fixes the problem of periodic network jitter caused by TCP connection monitoring (for example, cAdvisor configuration is deployed separately to monitor TCP connection) in high-concurrency scenarios.
- Optimizes soft interrupt for receiving network packets to enhance network performance.
Customized Container Features
Isolated display of container resources
- Adds a host-level switch: TencentOS Server realizes a LXCFS-like feature in its kernel. Instead of deploying nodes in the LXCFS file system or modifying POD spec, you only need to run the
sysctl -w kernel.stats_isolated=1 command to enable a global switch on nodes, and then files such as
/proc/meminfo obtained will be isolated by container.
- Adds a container-level switch: TencentOS Server adds a container-level switch
kernel.container_stats_isolated for special containers such as node monitoring component. When the host-level switch is enabled, you only need to run the
sysctl -w kernel.container_stats_isolated=0 command in the container startup script to disable the container-level switch, and then the host information will be obtained by reading files such as
/proc/meminfo in containers.
Kernel parameter isolation
TencentOS Server isolates the following kernel parameters by namespace:
Optimization of default container kernel parameters
TencentOS Server increases the default value of
net.core.somaxconn in the container network namespace to 4096, thus preventing packet loss caused by a full SYN queue in high-concurrence situations.
- TencentOS Server optimizes computing, storage, and network subsystems:
- Optimizes XFS memory allocation to resolve the XFS kmem_alloc failure alarm.
- Optimizes memory allocation for received network packets to resolve excessive memory usage when a large number of UDP packets are received.
- Limits the memory usage of the system page caches to maintain optimal service performance and prevent out-of-memory (OOM) errors.
- Customized based on the CentOS 7 software packages.
- User mode software packages are compatible with CentOS 7 and can be used directly on TencentOS Server.
- Updated and installed via Yellowdog Updater, Modified (YUM).
- Software packages in the Extra Packages for Enterprise Linux (EPEL) repository can be used after the epel-release package is installed via YUM.
- The Kdump feature is provided in the event of an operating system crash.
- Kernel live patching is supported.
TencentOS Server offers regular updates to enhance its security and features.