In the concurrent server design, a common method is to use fork to create sub-processes for each connection to process client requests separately.
The flowchart is as follows:
It can be seen that the parent process directly executes accept to wait for the next connection and does not use wait or waitpid to wait for the child
Server workflowWhen the./redis-server is executed, the server side of the Redis database starts.The main () function in REDIS.C is then executedThe main () function in which the work can be divided into the following sections:
1. Initializing server-side configuration information---initserverconfig ()
Label:When we read and write database files, these process activities trigger some run-time events when a file is read, written, or an error occurs. From a user's point of view, some of the time will be concerned about these events, especially our debugging, audit, service maintenance. For example, when database errors occur, column data is updated, CPU usage is high, and so on, tracking these states is very useful.This section covers key areas of the
ctest (I INT) ENGINE = NDBCLUSTER;> Insert into ctest () VALUES (1 );> SELECT * FROM ctest;
We can see 1 row returned information (return value 1 ).
If the above is normal, switch to Server2 and repeat the above test to observe the effect. If the operation succeeds, execute INSERT in Server2 and return to Server1 to check whether the operation is normal.If no problem exists, congratulations!
Vi. Destructive Testing====================Unplug the network cable of
The server shutdown process can be summarized as:
1. Start shutdown process
2. Server to create shutdown thread
3. Server stops receiving new connections
4. The server terminates the current activity
5. Storage engine is stop
performance on Linux, BSD, Solaris and other operating systems.Built-in memory storage modeTo improve performance, the data saved in memcached is stored in Memcached's built-in memory storage space. Because the data exists only in memory, restarting the memcached and restarting the operating system will cause all data to disappear. Additionally, when the content capacity reaches the specified value, the unused cache is automatically deleted based on the LRU (Least recently used) algorithm. The
Server does not have a Query Cache mechanism similar to MySql, but it has its own Cache mechanism. SQL Server does not directly cache the SQL query result set, but caches the queried Data pages (Data Buffer) It has read ), it also caches execution plans (process Cache Procedure Cache). Next we will talk about the well-known
The server shutdown process can be summarized as:
1. Start shutdown process
2. Server to create shutdown thread
3. Server stops receiving new connections
4. The server terminates the current activity
5. Storage engine is stop
Tornado Web Server multi-process start two methods, tornadoweb
I. Introduction to Tornado
Tornado is an open-source version of FriendFeed's Web server and common tools. Tornado differs significantly from the current mainstream Web Server framework (including most Python frameworks): It is a non-blocking
Server Process, serverprocess
1. After the client performs the update operation, how does one collaborate with others?
After the Client performs the update operation, the Server Process is actually completed. The steps are as follows:
1 ). the Data to be updated is directly updated in the Data buffer cache. If the Data
In server development, in order to make full use of multicore or even multiple CPUs, or to simplify the difficulty of writing logic, multi-processes (such as a process responsible for a logical) multithreading (assigning different users to different processes) or a co-process (different users are assigned different threads and switches to other threads when neede
programmers.then, describe what caused the problem that we found to be in need of the process. In high-concurrency applications, especially Web applications, each server has more than n connections and logical processing, and there is no logical association between each connection. Traditionally, for each connection request, a process or thread was created to ha
Test the code main function: Open a TCP server. The management process and the callback of the worker process start are then set to rename. Set the Pid_file to save the mast process initiated by the server.PHP//creating the server object, listening on the 127.0.0.1:9501 port
In Windows Server 2003 for each Web application, IIS 6.0 runs it with a separate w3wp.exe instance. W3wp.exe is also known as a worker process (one for each main header)
Ending a process directly in Task Manager does not work, it will start shortly after it finishes, and to end it can find the appropriate application pool in IIS to stop the corresponding applica
Implementing events for custom server controls is a more complex process. Not only do developers need to capture the postback event based on the methods described in the previous article, but they also sometimes need to participate in the postback data processing process. This article will introduce a method of processing the return data through a typical applica
Label:Originally intended to write about the transaction control process in the SSIS package, it was found that many of the basic concepts needed to be based on the isolation level of SQL Server transactions and transactions. So it took some time to get a good look at the concepts of transactions in SQL Server database, the ACID principle, the common problems in
relish the "Cache Hit ration" but still maintain a relatively high level of 98! This case tells us that the cache hit rate performance counter is often not a problem.
4, OK, in this case, who occupies the memory that belongs to my dear SQL Server? We continue, open wiindows task management, select the Process tab, click to show all the user processes, found that Svchost.exe occupies the vast majority
InfluxDB server startup process
Operating System: CentOS7.3.1611 _ x64
Go language version: 1.8.3 linux/amd64
InfluxDB version: 1.1.0
Source code path: github.com/influxdata/influxdb/#/influxd
Program entry (main. go ):
Func main (){Rand. Seed (time. Now (). UnixNano ())
M: = NewMain ()If err: = m. Run (OS. Args [1:]...); err! = Nil {Fmt. Fprintln (OS. Stderr, err)OS. Exit (1)}}
In the main function, call t
Brief introduction
When you develop a business process client program, you often need to query process instances, activities, and tasks within a process instance through certain business data standards. For example, you might want to find all the tasks associated with an ID's customer in the process instance.
When yo
Recently, comparing the features of PHP, Python, and Erlang found that PHP has many features that are not commonly used. Php cli can be used to implement many good applications. For example, search engine crawlers and long-running computing scripts can replace other languages for server O M. This is even more powerful for people familiar with PHP.
Why is PHP multi-process very good? The reason why most onl
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