Path) to maintain enough data segments, in fact, is 2 MSS size data Segment.anyway, These data are inflight data, what is infilght?It is sent to the unreachable, plus confirmed but not yet Confirmed. This is Inflight. How can I keep the ACK clock unblocked if I don't queue up? obviously, inflight more than 4 MSS segment data can, But now add a request, self-acti
###########################When a computer initiates a TCP connection request, the system responds to the ACK response packet.This option sets whether to delay the ACK response packet and sends it together with the data packet.High-speed networks and low load will slightly improve performance, but when the network connection is poor,If the recipient's computer does not receive a response, it will initiate a connection request continuously, which will make the network more congested and reduce pe
black flag painted black pedal? Feel is not weak strong, or the basic look did not enter, and is black under the painting is very bright hidden, then take off will not be negative scenery party slung the answer
17th Step
Continuous reduction of light color, understanding (right, left) eye (box) of the sluggish nature
18th Step
According to the line draft wipe into pupil and pupil pedal light area. Closed in the light area that liquid Mian, must carefully tie
), which is different from our previous practices. In short, it is more subtle!The process of sending a request from Dojo to the background is encapsulated in dojo. io. in the bind () method, we have our own front-and back-end communication mechanism, because we must find a way. io. bind () is replaced with our practice to achieve final integration, because the data interaction of Dojo ComboBox is encapsulated in DataProvider, because we only need to implement our own DataProvider, so we don't n
), which is different from our previous practices. In short, it is more subtle!The process of sending a request from Dojo to the background is encapsulated in dojo. io. in the bind () method, we have our own front-and back-end communication mechanism, because we must find a way. io. bind () is replaced with our practice to achieve final integration, because the data interaction of Dojo ComboBox is encapsulated in DataProvider, because we only need to implement our own DataProvider, so we don't n
", "parentClassName", constructor, and declarationBody), which is different from our previous practices. In short, it is more subtle!
The process of sending a request from Dojo to the background is encapsulated in dojo. io. in the bind () method, we have our own front-and back-end communication mechanism, because we must find a way. io. bind () is replaced with our practice to achieve final integration, because the data interaction of Dojo ComboBox is encapsulated in DataProvider, because we on
statistical data of (w/r) ticks (w/r) io ioticks. The kernel code is analyzed below, and the answer will naturally pop up.
Code Analysis (kernel version: 2.6.28)
The topic is directly switched here. For more information about IO stack, see other articles.
Let's first look at two structs:
Struct disk_stats: stores IO statistics for each block device. All statistics related to diskstats except inFlight are here. This structure is used to describe it
.
Comments: If your Linux client is using 2.6.32, the kernel recommendation is set to true before it can be closed directly.
rbd cache block writes upfront: If sync io is turned on, the default is False, and librbd the answer to be received after opening is Ceph OSD returned.
Reviews: When turned on, the performance is the worst, but the safest.
rbd readahead trigger requests: The number of consecutive requests that trigger a read-ahead
frequently encountered by many system administrators.
# Sh/etc/rc
Okay.
There are some kernel parameter adjustments that can improve or reduce the system performance, which we call sysctl. You can edit sysctl. conf to adjust it.
# Vi/etc/sysctl. conf
Kern. ipc. somaxconn = 65535
# Maximum number of connections
Net. inet. tcp. inflight. enable = 1
Net. inet. tcp. inflight. min = 6144
# Reduce laten
a small number of waiting queues, interactive connections, especially through slow modems, can also be used for low round-trip time operations.However, note that this only affects the data sent (upload/service side). No effect on data reception (download).Adjustment of Net.inet.tcp.inflight.stab is not recommended.The default value of this parameter is 20, which means that the 2 maximum packets are added to the calculation of the Bandwidth Delay product window.The extra window-like algorithm is
is usually set as a string, number, or Boolean. (Boolean with 1To 'yes', and 0 to 'no '). If you want to automatically set certain variables every time the machine starts, you can add them to the file/etc/sysctl. conf..
116. "11.12" section describes parameters for using sysctl to adjust disks.
117 and 11.13 adjust the kernel restrictions; 11.13.1 file/process restrictions; 11.13.1.1 Kern. maxfiles;Kern. maxusers;
118. The Kern. IPC. somaxconn sysctl variable limits the receipt of new TCPThe si
(Emqtt_session) maintains a inflight queue, which is used to reply to a message with a QoS greater than 0, and the default is to save 32 messages waiting to be answered, which will be placed in the waiting queue if the magnitude is exceeded. Therefore, the main memory consumption of the session process (emqtt_session) depends on how many messages are waiting to be answered, and the size of the packets that need to answer the message.Main CPU consumpt
Several important counters:
Packets_out: Packet after snd. una
Sacked_out: Packets confirmed by SACK (duplicate ack also causes this count to + 1 if no SACK exists)
Lost_out: Estimation of lost packets in the Network
Retrans_out: retransmission packet count
Here, lost_out is an estimated value, depending on the specific implementation.
Packet in_flight = packets_out + retrans_out-left_out residing in the network.
Left_out indicates the number of data packets that have left the network. left_out
dead TCP connection is a special problem of the system accessed by the dial-up user, because the user often disconnects the modem and does not properly close the active connection.Net. inet. tcp. always_keepalive = 1# If net. inet. ip. intr_queue_drops is increasing, you need to increase net. inet. ip. intr_queue_maxlen, preferably 0.Net. inet. ip. intr_queue_maxlen = 1000# Prevent DOS attacks. The default value is 30000.Net. inet. tcp. msl = 7500# Receive all packets sent from a closed port an
. inet. udp. blackhole = 1
# Provide a buffer for network data connection
Net. inet. tcp. inflight. enable = 1
# If it is enabled, the data of each target address will be recorded in the route table and arp data table once it is successfully forwarded, saving the route computing time, however, a large amount of kernel memory is required to save the route table.
Net. inet. ip. fastforwarding = 0
# Enable the options POLLING function in kernel Compil
); ......}Before Kafka 0.9, the consumer group was maintained by ZK, but because of the "herd" and "split brain" problems, after redesign, in the new version by the broker cluster to select a node as coordinator, To resolve synchronization of individual consumer in group, such as Rebalance,failover,partition Assignment,offset CommitRefer to Kafka consumer design to reconstruct the original text:Https://cwiki.apache.org/confluence/display/KAFKA/Consumer+Client+Re-DesignHttps://cwiki.apache.org/
, but some dead connections can be identified and cleared. Dead TCP Connection
The connection is a special problem of the system accessed by the dial-up user, because the user often disconnects the modem and does not properly close the active connection.Net. inet. tcp. always_keepalive = 1# If net. inet. ip. intr_queue_drops is increasing, you need to increase net. inet. ip. intr_queue_maxlen, preferably 0.Net. inet. ip. intr_queue_maxlen = 1000# Prevent DOS attacks. The default value is 30000.N
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