many concurrent smtp connections

Recently, our website often reports a 503 error: "HTTP Error 503. The service is unavailable ". But it is normal to brush one or two times. It is estimated that the maximum number of concurrent connections of the website is exceeded. What is an HTTP connection? When a page is loaded, images, styles, and scripts are used. Do requests for these items share one connection or multiple

Apache is a cross-platform Web server, because of its simple and efficient, stable security features, is widely used in computer technology in all areas. Now, with its huge number of users, Apache has become the number one Web server for users.However, in a real production environment, it is still not possible to use the default configuration of Apache directly to act as a server. After all, in order to use Apache server more fully and rationally, we should make some necessary adjustments to Apa

The following articles will show you how to set the number of concurrent connections in Oracle, under what circumstances cannot be set, and related query solutions. The following is an introduction to the specific content of the article. I hope you will gain some benefits, OERR: ORA-12519 TNS: no appropriate service handler found Client Connection intermittent failure, error ORA-12519 Cause:thelistene

the 65536 ports provided by widows are used up, there will be a large number of time_wait statuses and no new connections will be established, then there will be timeout, resulting in a large number of concurrent users downtime. This seriously affects the initiation of concurrency. The problem has been submitted to the O M department, asking them to help. Solution: 1. Modify the TCPIP attribute value in

1. View the number of concurrent requests for the Web server (Nginx Apache) and its TCP connection status:netstat -n | awk ‘/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}‘Or:netstat -n | awk ‘/^tcp/ {++state[$NF]} END {for(key in state) print key,"t",state[key]}‘The returned results are generally as follows: Last_ack 5 (number of requests waiting to be processed)SYN_RECV 30Established 1597 (normal data transfer status, can be understood as

By viewing the Nginx concurrent connections, we can clear the load of the website. There are two ways to view Nginx concurrency (the reason is that I only know two ways), one is through the web interface, the other is through the command, the web view is more accurate than the command display result... by viewing the Nginx concurrent

area (you can set the color and width of this curve), which is the IIS connection curve of the website, A yellow curve is shown. It should be noted that the windows system monitor displays the number of concurrent IIS connections, not as shown in "website statistics" for the number of visitors within 15 minutes, therefore, you will find that the number of concurrent