Files

 algorithm

/

tuning_params_os.csv

Copy path

Blame

Blame

Latest commit

gaoruoshu

remove duplicate params in csv and yaml file

Jan 28, 2021

9e021ee · Jan 28, 2021

History

History

250 lines (247 loc) · 40.8 KB

/

tuning_params_os.csv

Top

File metadata and controls

• Preview
• Code
• Blame

250 lines (247 loc) · 40.8 KB

Raw

1	Category	name (Parameter to be adjusted)	desc (Parameter description)	get (Command for querying parameter values.)	set (Command for setting parameter values)	needrestart(Whether require restart or not)	type (discrete/continuous)	options (For the discrete type, use";"to split different values.)	dtype (For discrete, the parameter value type can only be int or string.)	scope (Minimum value of the parameter)	scope (Maximum Value of the parameter)	step (Step of the parameter value)	items (Enumerated values out of parameter values. Use ";" to split different values)	select (whether to select the parameter)
2	Kernel scheduling parameters	kernel.sched_migration_cost_ns	This variable is used to determine whether a process is still hot. If the running time of a process is shorter than the value of this variable, the kernel considers that the code of the process is still in the cache. Therefore, the process is still hot and is not considered during migration.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	100000	5000000	100000		yes
3		kernel.sched_cfs_bandwidth_slice_us	Fixed size of the time slice applied for from the global time pool	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1000	50000	1000		yes
4		kernel.sched_wakeup_granularity_ns	This variable indicates the base of the minimum time that a process should run after it is woken up. The smaller the base, the higher the probability of preemption.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1000000	100000000	1000000		yes
5		kernel.sched_latency_ns	Maximum running time of a running process.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1000000	100000000	1000000		yes
6		kernel.sched_nr_migrate	How Many Processes Can Be Moved to Another CPU at a Time When Load Balancing Is Performed in the Case of Multiple CPUs?	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1	128	1		yes
7		kernel.sched_min_granularity_ns	Minimum running time of a process on the CPU. During this time, the kernel does not proactively select other processes for scheduling (in nanoseconds).	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1000000	100000000	1000000		yes
8		kernel.sched_tunable_scaling	Update method used when the kernel attempts to adjust the values of sched_min_granularity, sched_latency, and sched_wakeup_granularity. The value 0 indicates that the value is not adjusted, and the value 1 indicates that the value is adjusted based on the number of CPUs, 2: The linear proportion is adjusted based on the number of CPUs.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1; 2	string					yes
9	Network adapter parameters	transparent_hugepage.defrag	Enabling or Disabling Transparent Hugepages	cat /sys/kernel/mm/transparent_hugepage/defrag | sed -n 's/.*\[\(.*\)\].*/\1/p'	echo $value > /sys/kernel/mm/transparent_hugepage/defrag	FALSE	discrete	always;defer;defer+madvise;madvise;never	string					yes
10		transparent_hugepage.enabled	Enabling or Disabling Transparent Hugepages	cat /sys/kernel/mm/transparent_hugepage/enabled | sed -n 's/.*\[\(.*\)\].*/\1/p'	echo $value > /sys/kernel/mm/transparent_hugepage/enabled	FALSE	discrete	always; madvise; never	string					yes
11		net.netfilter.nf_conntrack_max	Maximum number of tracing connections When a container is used, the nf_conntrack module cannot be disabled. Therefore, kernel parameters related to nf_conntrack need to be added to the /etc/sysctl.conf file to prevent packet loss caused by full table records.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	67108864	1		yes
12		net.mtu	Indicates the maximum transmission unit of the network,	ifconfig @netdev | grep mtu | awk '{print $4}'	ifconfig @netdev mtu $value	FALSE	discrete		int	500	9000	500		yes
13		net.tx-frames	Configuring NIC Interrupt Combination	ethtool -c @netdev | grep tx-frames: | awk '{print $2}'	ethtool -C @netdev tx-frames $value	FALSE	discrete		int	0	64	2		yes
14		net.rx-frames	Configuring NIC Interrupt Combination	ethtool -c @netdev | grep rx-frames: | awk '{print $2}'	ethtool -C @netdev rx-frames $value	FALSE	discrete		int	0	64	2		yes
15		net.tx-usecs	Configuring NIC Interrupt Combination	ethtool -c @netdev | grep tx-usecs: | awk '{print $2}'	ethtool -C @netdev tx-usecs $value	FALSE	discrete		int	2	64	2		yes
16		net.rx-usecs	Configuring NIC Interrupt Combination	ethtool -c @netdev | grep rx-usecs: | awk '{print $2}'	ethtool -C @netdev rx-usecs $value	FALSE	discrete		int	2	64	2		yes
17		net.combined	Set the length and number of NIC queues.	ethtool -l @netdev | grep Combined | awk '{print $2}' | tail -n 1	ethtool -L @netdev combined $value	FALSE	discrete		int	1	32	1		yes
18		net.adaptive-rx	Sets whether to enable interrupt combination auto-sensing for a NIC.	ethtool -c @netdev | grep Adaptive | awk '{print $3}'	ethtool -C @netdev adaptive-rx $value	FALSE	discrete	on; off	string					yes
19		net.adaptive-tx	Sets whether to enable interrupt combination auto-sensing for a NIC.	ethtool -c @netdev | grep Adaptive | awk '{print $5}'	ethtool -C @netdev adaptive-tx $value	FALSE	discrete	on; off	string					yes
20		net.tx-ring buffer size	Indicates the ring buffer size of the NIC.	ethtool -g @netdev | tail -n 2 | head -n 1 | awk '{print $2}'	ethtool -G @netdev tx $value	FALSE	discrete		int	256	16384	256		yes
21		net.rx-ring buffer size	Indicates the ring buffer size of the NIC.	ethtool -g @netdev | tail -n 5 | head -n 1 | awk '{print $2}'	ethtool -G @netdev rx $value	FALSE	discrete		int	256	16384	256		yes
22		net.generic-receive-offload	Whether reassembling small packets into larger ones	ethtool -k @netdev | grep "generic-receive-offload" | awk '{print $2}'	ethtool -K @netdev gro $value	FALSE	discrete	on;off	string					yes
23		net.generic-segmentation-offload	Whether reassembling small packets into larger ones	ethtool -k @netdev | grep "generic-segmentation-offload" | awk '{print $2}'	ethtool -K @netdev gso $value	FALSE	discrete	on;off	string					yes
24		net.tcp-segmentation-offload	Wheth allow a device to segment a single frame into multiple frames with a data payload size specified in skb_shinfo()->gso_size.	ethtool -k @netdev | grep "tcp-segmentation-offload" | awk '{print $2}'	ethtool -K @netdev tso $value	FALSE	discrete	on;off	string					yes
25		sunrpc.tcp_slot_table_entries	The Linux NFS client controls the number of concurrent NFS requests. If this parameter is set to a small value, the I/O performance is poor. By default, the maximum value of this parameter for the compiled kernel is 256. You can increase the value of this parameter to achieve better performance.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	4	256	4		no
26		sunrpc.udp_slot_table_entries	The Linux NFS client controls the number of concurrent NFS requests. If this parameter is set to a small value, the I/O performance is poor. By default, the maximum value of this parameter for the compiled kernel is 256. You can increase the value of this parameter to achieve better performance.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	4	256	4		no
27	Kernel resource parameters	kernel.pid_max	Maximum process ID.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1048576	4194304	1048576		yes
28		kernel.shmmni	Maximum number of shared memory segments in the system.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1024	16384	1024		yes
29		kernel.shmmax	The maximum size, in bytes, of the shared memory segment allowed by the system.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	17179869184	68719476736	17179869184		yes
30		kernel.shmall	The total amount of shared memory available on the system in bytes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1073741824	8589934592	1073741824		yes
31		kernel.core_uses_pid	Whether to add the application pid to the core file name as an extension. 0: no 1: add	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
32		kernel.msgmni	System Message Queue Length	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	8000	128000	8000		yes
33		kernel.msgmax	Maximum number of bytes of a single message in a message queue.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	4096	1048576	4096		yes
34		kernel.msgmnb	Maximum length of bytes in a single message queue	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	4096	1048576	4096		yes
35		kernel.sem	The file contains four values: 1. Maximum number of signals of the same type (semmsl) 2. Maximum number of signals in the system, =semmni*semmsl (semmns) 3. Maximum number of operations (maximum number of semaphores that can be invoked) contained in each system invoking (semopm) 4. Maximum number of signal types in the system. A signal identifier represents a type (semmni).	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	16000 512000000 256 16000;32000 1024000000 500 32000;64000 2048000000 1000 64000	string					yes
36		kernel.hung_task_timeout_secs	Timeout interval of a hung_task (in seconds). When a process is in the TASK_UNINTERRUPTIBLE state for a period longer than the timeout interval, a hung_task occurs.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	30	1200	30		yes
37		kernel.nmi_watchdog	Enabling nmi_watchdog 0: disabled 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
38		kernel.sched_rt_runtime_us	This parameter, together with sched_rt_period, determines the period of the real-time process.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	950000	1000000	10000		yes
39		kernel.timer_migration	Disable Clock Migration	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
40		kernel.threads-max	Maximum number of processes (including threads) in the system	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	655360	65536000	655360		yes
41		kernel.sysrq	The file specifies a non-zero value, which activates the sysrq key on the keyboard.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
42		kernel.sched_autogroup_enabled	When enabled, the kernel creates task groups to optimize desktop program scheduling. 0: disabled 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
43		kernel.numa_balancing	Specifies whether to enable NUMA automatic balancing.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
44		kernel.randomize_va_space	Setting Memory Address Randomization	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	2	1		yes
45		kernel.dmesg_restrict	Which users are restricted from viewing syslogs? 0: no restriction 1: Only privileged users can view the information.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0;1	string					yes
46	Virtual memory and buffer/cache parameters	vm.swappiness	A larger value indicates that the swap partition is used more actively. A smaller value indicates that the memory is used more actively.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	100	1		yes
47		vm.vfs_cache_pressure	Indicates the tendency of the kernel to reclaim the memory used for directory and inode cache.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	500	50		yes
48		vm.dirty_background_ratio	When the percentage of dirty pages reaches dirty_background_ratio, the write function wakes up the flusher thread of the kernel to write back dirty page data until the percentage is less than the value of dirty_background_ratio.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	100	1		yes
49		vm.dirty_ratio	The percentage of dirty data in the memory cannot exceed this value.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	100	1		yes
50		vm.stat_interval	VM information update frequency (in seconds)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1	100	1		yes
51		vm.dirty_expire_centisecs	Expiration time of dirty data. When the flusher thread of the kernel is woken up after the expiration time, dirty data is written back to the disk. The unit is 1% second.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	100	1000	100		yes
52		vm.dirty_writeback_centisecs	Sets the interval for waking up the flusher kernel thread. This thread is used to write dirty pages back to the disk. The unit is 1% second.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	100	1000	100		yes
53		vm.overcommit_ratio	When overcommit_memory is set to 2, the percentage of physical RAM that is considered is set.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	100	10		yes
54		vm.overcommit_memory	Indicates whether to allow excessive memory allocation. The process can allocate more memory than it actually uses.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
55		vm.min_free_kbytes	Size of memory reserved in each memory area, in KB.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	10240	1024000	10240		yes
56		vm.page-cluster	Number of pages written to the swap partition each time.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	8	1		yes
57		vm.max_map_count	Defines the maximum memory area that a process can have.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	100000	10000000	100000		yes
58		vm.zone_reclaim_mode	This parameter is valid only when CONFIG_NUMA is enabled. zone_reclaim_mode is used to control how to reclaim memory when the memory domain OOM is enabled.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1; 2; 4	string					yes
59		vm.watermark_scale_factor	Controls the radical degree of the kswapd process, that is, how much memory needs to be released for the system (NUMA node) from wakeup to hibernation.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	10	1000	10		yes
60		vm.numa_stat	This command is used to set the data statistics during NUMA running. When the memory is insufficient, this command can be set to 0 to reduce the statistics precision.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
61		vm.drop_caches	Releases the cache. The cache is released each time the parameter is modified.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	1; 2; 3	string					yes
62	File system parameters	fs.inotify.max_user_watches	Sets the number of processes for each user to run the inotifywait or inotifywatch command.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	4096	819200	4096		yes
63		fs.nr_open	Maximum number of file handles that can be concurrently opened by a process	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	10240	1024000	10240		yes
64		fs.file-max	Number of file handles that can be opened by all processes in the system at the same time	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	102400	10240000	102400		yes
65		fs.aio-max-nr	Maximum number of AIO requests	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	102400	10240000	102400		yes
66		fs.inotify.max_user_instances	Maximum number of inotify instances that can be started by each user	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	64	65535	64		yes
67		fs.suid_dumpable	This value can be used to query and set the core dump mode for setuid or otherwise protected/tainted binaries. 0: default 1: debug 2: suidsafe	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	2	1		yes
68	Block storage device parameters	blockdev	Disk prefetch settings	/sbin/blockdev --getra /dev/@block	/sbin/blockdev --setra $value /dev/@block	FALSE	discrete		int	0	2147483648	8		yes
69		block.low_latency	Enables (1) or disables (0) the low latency mode	cat /sys/block/@block/queue/iosched/low_latency	echo $value > /sys/block/@block/queue/iosched/low_latency	FALSE	discrete	0;1	string					no
70		block.fifo_batch	This parameter is valid only for the Deadline scheduling policy. The number of read or write operations issued in a single batch. The default value is 16. The higher the value, the higher the throughput, but also increases the latency.	cat /sys/block/@block/queue/iosched/fifo_batch	echo $value > /sys/block/@block/queue/iosched/fifo_batch	FALSE	discrete		int	1	128	1		yes
71		block.front_merges	This parameter is valid only for the Deadline scheduling policy. When a new request enters the queue, it can be merged if the requested sector is close to the current sector. The merge can be backward or forward. In some scenarios, forward merging is unnecessary. In this case, you can set this parameter to disable forward merging. By default, the deadline supports forward merging. If this parameter is set to 0, forward merging is disabled.	cat /sys/block/@block/queue/iosched/front_merges	echo $value > /sys/block/@block/queue/iosched/front_merges	FALSE	discrete	0;1	string					yes
72		block.read_expire	This parameter is valid only for the Deadline scheduling policy. This parameter specifies the expiration time of a read request, in milliseconds.	cat /sys/block/@block/queue/iosched/read_expire	echo $value > /sys/block/@block/queue/iosched/read_expire	FALSE	discrete		int	100	1000	100		yes
73		block.write_expire	This parameter is valid only for the Deadline scheduling policy. This parameter specifies the expiration time of a write request, in milliseconds.	cat /sys/block/@block/queue/iosched/write_expire	echo $value > /sys/block/@block/queue/iosched/write_expire	FALSE	discrete		int	1000	5000	10000		no
74		block.writes_starved	This parameter is valid only for the Deadline scheduling policy. This parameter specifies the number of read requests that can be sent after the read and write queues are not empty. A larger value indicates a higher priority for read batch processing.	cat /sys/block/@block/queue/iosched/writes_starved	echo $value > /sys/block/@block/queue/iosched/writes_starved	FALSE	discrete		int	1	10	1		yes
75		block.back_seek_max	This parameter is valid only for the CFQ/BFQ scheduling policy. Maximum range of backward addressing for the head	cat /sys/block/@block/queue/iosched/back_seek_max	echo $value > /sys/block/@block/queue/iosched/back_seek_max	FALSE	discrete		int	4096	1048576	4096		no
76		block.back_seek_penalty	This parameter is valid only for the CFQ/BFQ scheduling policy. Penalty coefficient for backward addressing. This value is compared with forward addressing. The preceding two parameters are set to prevent slow addressing caused by head seek jitter.	cat /sys/block/@block/queue/iosched/back_seek_penalty	echo $value > /sys/block/@block/queue/iosched/back_seek_penalty	FALSE	discrete		int	1	16	1		no
77		block.fifo_expire_async	This parameter is valid only for the CFQ/BFQ scheduling policy. Sets the timeout period of an asynchronous request. Synchronous requests and asynchronous requests are processed in different queues. During scheduling, the cfq process processes synchronous requests first and then asynchronous requests unless the asynchronous requests meet the preceding conditions.	cat /sys/block/@block/queue/iosched/fifo_expire_async	echo $value > /sys/block/@block/queue/iosched/fifo_expire_async	FALSE	discrete		int	50	1000	50		no
78		block.fifo_expire_sync	This parameter is valid only for the CFQ/BFQ scheduling policy. Set the timeout period of the synchronization request.	cat /sys/block/@block/queue/iosched/fifo_expire_sync	echo $value > /sys/block/@block/queue/iosched/fifo_expire_sync	FALSE	discrete		int	25	500	25		no
79		block.timeout_sync	This parameter is valid only for the CFQ/BFQ scheduling policy. The maximum time allocated to a device. When the addressing time of a device is long, increasing the time can improve the throughput.	cat /sys/block/@block/queue/iosched/timeout_sync	echo $value > /sys/block/@block/queue/iosched/timeout_sync	FALSE	discrete		int	16	1024	16		no
80		block.max_budget	This parameter is valid only for the CFQ/BFQ scheduling policy. Maximum number of queue services that can be allocated to a queue	cat /sys/block/@block/queue/iosched/max_budget	echo $value > /sys/block/@block/queue/iosched/max_budget	FALSE	discrete		int	0	0	0		no
81		block.slice_idle	This parameter is valid only for the CFQ/BFQ scheduling policy. A wait time is set. This allows the cfq to wait for a period of time before switching the cfq_queue or service tree to improve the throughput of the HDD.	cat /sys/block/@block/queue/iosched/slice_idle	echo $value > /sys/block/@block/queue/iosched/slice_idle	FALSE	discrete		int	0	16	2		no
82		block.slice_idle_us	This parameter is valid only for the CFQ/BFQ scheduling policy. Waiting time, in microseconds.	cat /sys/block/@block/queue/iosched/slice_idle_us	echo $value > /sys/block/@block/queue/iosched/slice_idle_us	FALSE	discrete		int	1000	16000	1000		no
83		block.strict_guarantees	This parameter is valid only for the CFQ/BFQ scheduling policy. When the request queue is empty, the request queue remains idle.	cat /sys/block/@block/queue/iosched/strict_guarantees	echo $value > /sys/block/@block/queue/iosched/strict_guarantees	FALSE	discrete	0;1	string					no
84		block.read_lat_nsec	This parameter is valid only for the Kyber scheduling policy. Target delay of the read request, in ns.	cat /sys/block/@block/queue/iosched/read_lat_nsce	echo $value > /sys/block/@block/queue/iosched/read_lat_nsec	FALSE	discrete		int	1000000	100000000	1000000		no
85		block.write_lat_nsec	This parameter is valid only for the Kyber scheduling policy. Target delay of a synchronous write request, in ns.	cat /sys/block/@block/queue/iosched/write_lat_nsec	echo $value > /sys/block/@block/queue/iosched/write_lat_nsec	FALSE	discrete		int	2000000	100000000	2000000		no
86		block.io_poll_delay	If polling is enabled, this parameter controls which type of polling is performed. The default value is -1, indicating traditional polling. In this mode, the CPU will not give up any time to repeatedly ask for completion. If set to 0, the mixed polling mode is used, and the kernel attempts to guess when the I/O is complete based on the training. Based on this guess, the kernel puts the process that made the IO request to sleep for a period of time before entering a traditional polling cycle. This mode may be slower than the purely traditional polling mode, but it may be more efficient. If this value is set to a value greater than 0, the kernel sets the process that issued the IO request to sleep for so many microseconds before entering a traditional poll.	cat /sys/block/@block/queue/io_poll_delay	echo $value > /sys/block/@block/queue/io_poll_delay	FALSE	discrete	0;-1	string					no
87		block.io_poll	Whether to use polling or interrupt processing for block devices. The polling policy is preferred for NVMe SSD devices.	cat /sys/block/@block/queue/io_poll	echo $value > /sys/block/@block/queue/io_poll	FALSE	discrete	0; 1	string					no
88		block.max_sectors_kb	Specifies the maximum size (in kilobytes) of the I/O request. The default value is 512 KB.	cat /sys/block/@block/queue/max_sectors_kb	echo $value > /sys/block/@block/queue/max_sectors_kb	FALSE	discrete		int	64	1024	64		yes
89		block.queue_depth	Block device queue depth	cat /sys/block/@block/device/queue_depth	echo $value > /sys/block/@block/device/queue_depth	FALSE	discrete		int	64	1024	64		yes
90		block.nr_requests	Limits the maximum number of read and write requests queued at the same time.	cat /sys/block/@block/queue/nr_requests	echo $value > /sys/block/@block/queue/nr_requests	FALSE	discrete		int	128	2048	64		yes
91		block.read_ahead_kb	Defines the number of kilobytes that the operating system will prefetch during the sequential read operation phase to store information that may be needed immediately in the page cache.	cat /sys/block/@block/queue/read_ahead_kb	echo $value > /sys/block/@block/queue/read_ahead_kb	FALSE	discrete		int	0	65536	1024		yes
92		block.rq_affinity	Whether I/O can be performed on different processors is not limited to the processor that sends the I/O request.	cat /sys/block/@block/queue/rq_affinity	echo $value > /sys/block/@block/queue/rq_affinity	FALSE	discrete	0; 1; 2	string					yes
93		block.add_random	Some I/O events affect the entropy pool of /dev/random.	cat /sys/block/@block/queue/add_random	echo $value > /sys/block/@block/queue/add_random	FALSE	discrete	0; 1	string					yes
94		block.rotational	Whether the storage device is a mechanical hard disk. If the storage device is a solid state disk, set this parameter to 0.	cat /sys/block/@block/queue/rotational	echo $value > /sys/block/@block/queue/rotational	FALSE	discrete	0; 1	string					yes
95		block.scheduler	Configure I/O scheduling. Deadline or noop is more suitable for MySQL database scenarios.	cat /sys/block/@block/queue/scheduler | sed -n 's/.*\[\(.*\)\].*/\1/p'	echo $value > /sys/block/@block/queue/scheduler	FALSE	discrete	mq-deadline; kyber; bfq; none	string					yes
96		block.write_cache	Whether to use the write back or write through cache policy	cat /sys/block/@block/queue/write_cache	echo $value > /sys/block/@block/queue/write_cache	FALSE	discrete	write back; write through	string					yes
97		block.nomerges	Most workloads benefit from request merges. However, disabling merges helps for debugging purposes. You can set this parameter to 0 to disable combination. Enabled by default (set to 1).	cat /sys/block/@block/queue/nomerges	echo $value > /sys/block/@block/queue/nomerges	FALSE	discrete	0; 1; 2	string					yes
98	Parameters related to the network software stack	net.core.netdev_budget	Number of network packets processed in each software interrupt	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	100	1000	100		yes
99		net.core.optmem_max	Maximum size of the buffer allowed by each socket(in bytes).	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	20480	204800	20480		yes
100		net.core.wmem_max	The maximum size of the system socket write buffer is increased to prevent buffer overflow caused by a large number of new connections. As a result, connections cannot be established. The default value is 229376. You are advised to change the value to 16777216.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1048576	67108864	1048576		yes
101		net.core.wmem_default	Default TCP send window size (bytes)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	8192	1048576	8192		yes
102		net.core.rmem_default	Sets the default buffer size (bytes) of the receive socket.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	8192	1048576	8192		yes
103		net.core.rmem_max	Maximum system socket read buffer The default value is 229376. You are advised to change the value to 16777216.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1048576	67108864	1048576		yes
104		net.core.netdev_max_backlog	Maximum number of packets that can be sent to the queue when each network interface receives packets faster than the kernel processes them	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1000	100000	1000		yes
105		net.ipv4.tcp_thin_linear_timeouts	Check whether the TCP stream is thin after the retransmission times out.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0;1	string					yes
106		net.unix.max_dgram_qlen	Maximum number of datagrams in a UDP queue	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	128	1048576	128		yes
107		net.core.somaxconn	Defines the maximum length of the listening queue of each port in the system. This is a global parameter. The default value is 128. You are advised to change the value to 1024.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	128	65536	128		yes
108		net.core.busy_poll	Timeout interval for performing the poll and select operations on network devices (us) by default. The value is determined by the number of sockets.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	200	10		yes
109		net.core.busy_read	Timeout interval for reading data frames in the device frame queue (us) by default. The recommended value is 50.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	200	10		yes
110		net.core.dev_weight	Maximum number of network packets that can be processed by each CPU in an NAPI interrupt	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	16	1024	16		yes
111		net.ipv4.tcp_keepalive_intvl	Indicates the frequency of sending TCP probe packets. The value multiplied by tcp_keepalive_probes indicates the duration when no TCP connection is available.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	30	300	15		yes
112		net.ipv4.tcp_keepalive_probes	This file indicates the maximum number of times that TCP keepalive detection is performed before a TCP connection is discarded. Keep-alive connections are sent only when the SO_KEEPALIVE socket option is turned on.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	3	144	3		yes
113		net.ipv4.tcp_keepalive_time	Interval for sending keepalive detection messages(in seconds). This parameter is used to check whether the TCP connection is valid.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	600	36000	600		yes
114		net.ipv4.tcp_tw_reuse	The value 1 indicates that TIME-WAIT sockets can be used for new TCP connections, and the value 0 indicates that TIME-WAIT sockets are disabled.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0;1;2	string					yes
115		net.ipv4.tcp_window_scaling	The window scaling defined in RFC 1323 is enabled. To support a TCP window larger than 64 KB, this parameter must be set to 1. The maximum size of a TCP window is 1 GB. This parameter takes effect only when both parties of a TCP connection are enabled.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0;1	string					yes
116		net.ipv4.tcp_fin_timeout	Maximum duration for a socket to remain in the FIN_WAIT_2 state.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1	120	1		yes
117		net.ipv4.udp_mem	The file saves three values: low: When the number of memory pages used by UDP is less than the value of this parameter, UDP does not release memory. assure: When the number of memory pages used by UDP exceeds the value of this parameter, UDP attempts to stabilize the memory usage and enters the pressure mode. When the memory usage is less than the value of low, UDP exits the pressure mode. high: indicates the number of pages that can be used by all UDP sockets to queue and buffer datagrams.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	12582912 16777216 25165824;25165824 33554432 50331648;50331648 100663296	string					yes
118		net.ipv4.tcp_mem	TCP overall cache setting, which controls all TCP memory usage (in pages). The parameter indicates the no-pressure value of the TCP overall memory, the threshold for enabling the pressure mode, and the maximum usage value in sequence. This parameter is used to control whether the new cache is successfully allocated.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	6168306 8224411 12336612;12336612 16448822 24673224	string					yes
119		net.ipv4.tcp_rmem	Size of the read buffer. The first value is the minimum value of the read buffer, the third value is the maximum value, and the middle value is the default value. The default value is 4096 87380 6291456. You are advised to change the value to 4096 87380 16777216.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	4096 16384 4194304;4096 32768 8388608;4096 65536 16777216	string					yes
120		net.ipv4.tcp_wmem	Size of the write buffer. The first value is the minimum value of the read buffer, the third value is the maximum value, and the middle value is the default value. The default value is 4096 16384 4194304. You are advised to change the value to 4096 65536 16777216.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	4096 16384 4194304;4096 32768 8388608;4096 65536 16777216	string					yes
121		net.ipv4.tcp_fastopen	Whether to enable the TCP quick open mode is to avoid the three-way handshake of hot requests. This greatly improves the performance in the scenario where small objects are moved.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	1; 2; 4	string					yes
122		net.ipv4.tcp_synack_retries	For the remote connection request SYN, the kernel sends a SYN + ACK packet to acknowledge the receipt of the previous SYN connection request packet. It's called a three-way handshake. This parameter determines the number of SYN+ACK packets sent by the kernel before the kernel discards the connection.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	3	64	1		yes
123		net.ipv4.tcp_syn_retries	Number of times that the local device retransmits TCP SYN packets due to timeout. The value cannot be greater than 255. This parameter is valid only for outgoing connections. For incoming connections, this parameter is controlled by tcp_retries1.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	3	64	1		yes
124		net.ipv4.tcp_moderate_rcvbuf	Whether to adjust the receive buffer when receiving data 0: no adjustment 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
125		net.ipv4.tcp_timestamps	Indicates whether to enable the calculation of the RTT in a more accurate way than timeout retransmission (see RFC 1323). This option should be enabled for better performance. 0: no 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
126		net.ipv4.tcp_dsack	Indicates whether to allow TCP to send two identical SACKs. 0: disabled 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
127		net.ipv4.tcp_fack	Enables the forwarding acknowledgment. The selective acknowledgment (SACK) can be performed to reduce the occurrence of congestion. This option should also be enabled.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
128		net.ipv4.tcp_sack	Indicates whether to enable the selective acknowledgment function. This function improves the performance by selectively responding to out-of-order received packets. In this way, the sender can send only lost packet segments. This function should be enabled for WAN communication, however, this increases the CPU usage. 0: no 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
129		net.ipv4.tcp_low_latency	Allows the TCP/IP stack to adapt to low latency in high throughput scenarios. This option is generally disabled. (But when building a Beowulf cluster, it helps to open it.) 0: disabled 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
130		net.ipv4.tcp_adv_win_scale	Calculating the Buffer Overhead	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	4	1		yes
131		net.ipv4.route.max_size	Maximum number of entries in the routing cache. If the number of entries in the routing cache exceeds the maximum, the old entries are cleared.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	67108864	2080374784	67108864		yes
132		net.ipv4.tcp_max_tw_buckets	Reduce the number of TIME_WAIT connections to prevent excessive TIME_WAIT connections from occupying network resources and increasing the latency. The default value is 2048. You are advised to change the value to 360000.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	32768	1048576	32768		yes
133		net.ipv4.tcp_max_syn_backlog	Indicates the length of the SYN queue. A larger queue length can accommodate more network connections waiting for connections. The default value is 2048. You are advised to change the value to 8192.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	1024	262144	1024		yes
134		net.ipv4.tcp_max_orphans	Number of sockets that can be processed by the system and do not belong to any process. When a large number of connections need to be quickly established, pay attention to this parameter.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	65536	16777216	65536		yes
135		net.ipv4.tcp_ecn	Indicates whether to enable the direct TCP congestion notification function. 0: disabled; 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1; 2	string					yes
136		net.ipv4.ip_forward	Indicates whether to enable IPv4 IP forwarding. 0: disabled 1: enabled	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
137		net.ipv4.conf.default.rp_filter	The kernel sets the policy for responding to ARP queries.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
138		net.ipv4.ip_local_port_range	The range of available ports has been increased to prevent performance deterioration caused by continuous search of available ports for new connections when a large number of connections occupy ports.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	32768 60999; 1024 65535; 8192 65535	string					yes
139		net.ipv4.tcp_no_metrics_save	After a TCP connection is closed, the saved parameters can be used to initialize the connection when the same connection is created next time as long as dst_entry is valid.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
140		net.ipv4.ip_default_ttl	Specifies the lifetime of IP packets sent from the local device. The value is an integer ranging from 0 to 128. The default value is 64.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	8	128	8		yes
141		net.ipv4.ip_no_pmtu_disc	Setting the MTU for Automatic Socket Detection	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
142		net.ipv4.tcp_retries2	The number of retries required before discarding an active (established traffic condition) TCP connection. The default value is 15.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	3	30	1		yes
143		net.ipv4.tcp_orphan_retries	Number of retries before the local end discards the TCP connection. The default value is 7.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	15	1		yes
144		net.ipv4.tcp_syncookies	Indicates whether to enable the TCP synchronization label (syncookie).	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
145		net.ipv4.tcp_reordering	Maximum number of reordered data packets in TCP flows	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	2	10	1		yes
146		net.ipv4.tcp_retrans_collapse	Provides compatibility for bugs on some printers. (Generally, this support is not required. You can disable it.)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
147		net.ipv4.tcp_congestion_control	TCP congestion scheduling algorithm	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	cubic; reno; bbr	string					yes
148		net.ipv4.conf.default.promote_secondaries	0: When the primary IP address of an interface is removed, all secondary IP addresses are deleted. 1: When the primary IP address of an interface is removed, the secondary IP address becomes the primary IP address.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
149		net.ipv4.conf.all.promote_secondaries	0: When the primary IP address of an interface is removed, all secondary IP addresses are deleted. 1: When the primary IP address of an interface is removed, the secondary IP address becomes the primary IP address.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
150		net.ipv4.conf.all.accept_redirects	Receives and sends ICMP redirection messages. The default value is True for hosts and False for routers. 0: disabled 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
151		net.ipv4.conf.default.accept_redirects	Receives and sends ICMP redirection messages. The default value is True for hosts and False for routers. 0: disabled 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
152		net.ipv4.conf.all.secure_redirects	Receives only ICMP redirect messages sent to gateways in the default gateway list. 0: disabled 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
153		net.ipv4.conf.default.secure_redirects	Receives only ICMP redirect messages sent to gateways in the default gateway list. 0: disabled 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
154		net.ipv4.icmp_echo_ignore_broadcasts	Ignore all received ICMP Echo request broadcasts. 0: not ignore 1: ignore	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
155		net.nf_conntrack_max	Maximum number of ip_conntrack structures in the memory	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	65536	1048576	65536		yes
156		net.netfilter.nf_conntrack_tcp_timeout_established	Timeout interval for TCP in the established state (s)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	108000	1728000	108000		yes
157		net.netfilter.nf_conntrack_tcp_timeout_close_wait	Timeout interval for TCP in close wait state (s)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	15	240	15		yes
158		net.netfilter.nf_conntrack_tcp_timeout_fin_wait	Timeout interval for TCP in the fin wait state (s)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	30	480	30		yes
159		net.netfilter.nf_conntrack_tcp_timeout_time_wait	Timeout interval for TCP in time wait state (s)	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	30	480	30		yes
160		net.ipv4.conf.default.forwarding	Enable the forwarding function on the interface. 0: disabled 1: yes	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete	0; 1	string					yes
161		net.core.rps_sock_flow_entries	RFS (Receiver Flow Control) extends the performance of RPS to increase the CPU cache hit ratio and reduce network latency.	sysctl -n @name	sysctl -w @name=$value	FALSE	discrete		int	0	131072	1024		yes
162		net.ipv4.tcp_min_tso_segs	Minimal number of segments per TSO frame.	sysctl -n @name	sysctl -w @name=$value	FALSE	continuous		int	1	16	1		yes
163	others	login.UserTasksMax	Limit the maximum number of operating system tasks that can be run concurrently by each user	cat /etc/systemd/logind.conf | grep -w "^UserTasksMax" | awk -F "=" '{print$2}'	sed -i "s/UserTasksMax=.*/UserTasksMax=$value/" /etc/systemd/logind.conf	FALSE	continuous		int	1024	1048576			yes
164		ulimit.nofile	Maximum number of files that can be used by a user.	ulimit -n	ulimit -n $value	FALSE	discrete		int	1024	10240	1		yes