Category : network

HTTPRespond to common status codes Blog link:Aspects of Network Knowledge Status code describe 100-199 Successful receipt of the request requires the client to continue submitting the next request to complete the entire process. 200-299 Successfully received the request and completed the whole processing process. Commonly used200 300-399 In order to complete the request, the requirements ..

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PIO and DMA It is necessary to briefly talk about the data transfer mode between slow I/O devices and memory. PIOLet’s take disk as an example. Long ago, the data transfer between disk and memory was controlled by CPU. That is to say, if we read disk files into memory, the data would be stored ..

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For many actual servers at the back end of the load balancing scheduler, we can fully understand their status in real time through the monitoring system. Once a server is found to have failed, it needs to be immediately removed from the scheduling policy, that is, DNS records directed to the server are suspended, so ..

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In spite of this, the gateway serving as the NAT server has also become a bottleneck restricting the expansion of the cluster. We know that the NAT server will not only forward the user’s request to the actual server, but also forward the response from the actual server to the user. Therefore, when the actual ..

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When it comes to data transmission, that is, the journey of data from the host to the line, the following steps are generally required:The application program must first write the data to be sent into the memory address space of the process. Developers who are familiar with network programming must be very familiar with this ..

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netsat netstat -ant Get root@f6c0aba5201d:/# netstat -ant Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp6 0 0 :::8080 :::* LISTEN tcp6 52 0 172.17.0.2:8080 192.168.99.1:56750 ESTABLISHED tcp6 0 0 172.17.0.2:8080 192.168.99.1:56503 TIME_WAIT tcp6 52 0 172.17.0.2:8080 192.168.99.1:56788 ESTABLISHED tcp6 0 0 172.17.0.2:8080 192.168.99.1:56686 TIME_WAIT tcp6 0 0 172.17.0.2:8080 ..

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Order Regarding tomcat’s parameters, it is easy to confuse the following parameters: acceptCount, maxConnections, maxThreads, minSpareThreads. Let’s make some clarification here. Different levels MaxThreads and minSpareThreads are the configuration parameters of tomcat worker thread pool. maxThreads is equivalent to maxPoolSize of jdk thread poo l, while minSpareThreads is equivalent to corePoolSize of jdk thread pool. ..

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Cache-Control has many parameters to choose from, which are very important for cache control. Parameters include: Public: Responses are cached and can be shared among multiple users. Private: The response can only be used as a private cache. For example, in a browser, it cannot be shared among users, so it cannot be cached by ..

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three-way handshake ListenOverflows root@b5dbe93bcb04:/opt# netstat -s | grep listen 22438 times the listen queue of a socket overflowed Tcp_v4_syn_recv_sock (): after the last step of the three-way handshake is completed, the Accept queue queue (full connection queue, its size is min (/proc/sys/net/core/somaxconn, backlog)) is increased by 1 when it exceeds the upper limit. ListenDrops root@b5dbe93bcb04:/opt# ..

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Queue and Parameters The server-side semi-connection queue (syn queue) In the three-way handshake protocol, the server maintains a semi-connection queue, which creates an entry for each client’s SYN packet (the server has already created the request_sock structure when it receives the SYN packet and stored it in the semi-connection queue). The entry indicates that the ..

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Direct read /proc/net/dev public class NetStatReader implements MetricsReader { private static File netstat = new File(“/proc/net/dev”); private static final Pattern dline = //rx //tx // device_name -bytes packets errs drops fifo frame com mult -bytes packets errs drops fifo frame com mult Pattern.compile(“^ *([A-Za-z]+[0-9]*):\\D*(\\d+)\\D+(\\d+)\\D+(\\d+)\\D+(\\d+)\\D+\\d+\\D+\\d+\\D+\\d+\\D+\\d+\\D+(\\d+)\\D+(\\d+)\\D+(\\d+)\\D+(\\d+)\\D+\\d+\\D+\\d+\\D+\\d+\\D+\\d+.*”); private static final Logger LOG = Logger.getLogger(NetStatReader.class.getName()); @Inject private Configuration conf; ..

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