proc hadoop

Chapter 1 Meet HadoopData is large, the transfer speed is not improved much. it's a long time to read all data from one single disk-writing is even more slow. the obvious way to reduce the time is read from multiple disk once.The first problem to solve is hardware failure. The second problem is that most analysis task need to be able to combine the data in different hardware. Chapter 3 The Hadoop Distributed FilesystemFilesystem that manage storage h

The use of Lesson:p Roc Sub-function1. Proc Sum {arg1 arg2} {Set x [Expr $arg 1+ $arg 2];return $x}Puts "The sum of 2 + 3 is: [Sum 2 3]\n\n"[Syntax]: proc procname {var1 var2 ...} {Body}Description1. The proc command has three parameters: ProcName is the defined procedure name; {var1 var2 ...} is the input, outputA parameter list; body is a Process execution comm

The procedure in the previous section was exciting, and we implemented a MYPRINTK printing function ourselves. But there is a fatal flaw in this function, which is that you can only use the CAT/PROC/MYMSG command once to read the value of Mylog_buf. This is because the read to the end will appear: Mylog_r = = Mylog_w, indicating that the buffer is empty, the next time you can not read the data. In this section we are going to solve this problem, and a

The content in/proc/net/tcp is printed by the Tcp4_seq_show () function, which has three printing forms, and here we have this list of states that are the tcp_seq_state_listening or tcp_seq_state_established case is as follows:The result of Netstat is to read the/proc/net/tcp file.How to view the creation time of a connection1.NESTAT-APN | grep XXX checks to see the corresponding connected process PID and p

The/proc file system is a pseudo-file system that only exists in memory and does not occupy external memory space.It provides an interface for accessing system kernel data in a file system manner.Users and applications can get system information through proc, and can change certain parameters of the kernel.Because the information of the system, such as the process, is dynamically changed, so when the user o

LinuxCompositionThe hardware device also has corresponding entries/dev /Special files in Proc allow high-level access to driver and kernel information Ls/proc CAT/proc/cpuinfo (CPU Information) CAT/proc/meminfo (memory information) Every time you read the contents of these files, the information will be updated in

1, create the API for the node under the/proc file systemHttp://www.cnblogs.com/ziziwu/archive/2011/10/20/2218975.htmlstruct Proc_dir_entry *create_proc_entry (const char *name, mode_t mode, struct proc_dir_entry *parent);The parameters are/proc file name, mask, parent directory, respectively.[CPP]View Plaincopy struct Proc_dir_entry { unsigned int low_ino; umode_t mode; nlink_t Nlink; kuid_t u

1, create the API for the node under the/proc file systemHttp://www.cnblogs.com/ziziwu/archive/2011/10/20/2218975.htmlstruct Proc_dir_entry *create_proc_entry (const char *name, mode_t mode, struct proc_dir_entry *parent);The parameters are/proc file name, mask, parent directory, respectively.[CPP]View Plaincopy struct Proc_dir_entry { unsigned int low_ino; umode_t mode; nlink_t Nlink; kuid_t u

Reprinted from: http://blog.csdn.net/pppjob/article/details/4060336Under Linux, CPU utilization is divided into user state, System State and idle state, respectively, the CPU is in user state execution time, system kernel execution time, and idle system process execution time, the sum of which is the total CPU time, when there is no user process, system process, etc. need to execute, The CPU executes the system default idle process. From the normal way of thinking, CPU utilization is the proport

When doing kernel-driven development, you can use the files under/proc to get the appropriate information for debugging.Most of the files under/proc are read-only, but for the completeness of the example, a write method is provided.Method One: Use Create_proc_entry to create the proc file (simple, but the write operation has the danger of buffer overflow);Method

1. In proc and lambda, the return keyword has different meanings :In proc, return only means returning from this lambda.In a lambda, return is not returned from the proc, but rather from the scope in which the proc is defined. Copy Code code as follows: def One_method p = Proc.new{return #调用这个块的时候, returns

CSDN GitHub Kptr_restrict to a pointer in the user space kernel (/proc/kallsyms-modules displays value all 0) Linuxdevicedrivers/study/debug/filesystem/procfs/kptr_restrict This work uses the Knowledge sharing signature-non-commercial use-the same way Shares 4.0 international License Agreement to authorize, reprint please indicate the source, thank the cooperation Because of my technical level and limited knowledg

,/etc/x11,/etc/sysconfig,/etc/ Xinetd.d remember to backup before modifying the configuration file. Note:/etc/x11 stores settings related to x Windows. /home:System Default User home directory, add user account, the user's home directory is stored in this directory, ~ represents the current user's home directory, ~test represents the user test home directory. Suggest separate partitions and set up larger disk space for users to store data /lib:/usr/lib:/usr/local/lib: The system uses the functio

Today, when it comes to getting the total size of the available memory space on the phone, it is not advisable to find that the minimum supported version of the method is 16 by the following method.1 Public Static Longgettotalspace (Context ctx) {2 //1. Create a Activitymanager object3Activitymanager am =(Activitymanager)4 Ctx.getsystemservice (context.activity_service);5 //2 Getting an object that encapsulates memory information6Memoryinfo Memoryinfo =NewMemoryinfo ();//assigning val

Proc/version We usually use CAT/proc/version to obtain the version number of our kernel, but how is it generated? Let's see fs/proc/version. C. static int version_proc_show(struct seq_file *m, void *v){seq_printf(m, linux_proc_banner,utsname()->sysname,utsname()->release,utsname()->version);return 0;}static int version_proc_open(struct inode *inode, struct file *

2016.11.8Brother K has 2 servers using the Unison+inotify to reach the site folder synchronization effectToday suddenly found that inotify occupy a large CPU, you can use the top command to viewOpen the INotify log to see whyFind this errorFailed to Watch/opt; Upper limit on inotify watches reached!Please increase the amount of inotify watches allowed per user via '/proc/sys/fs/inotify/max_user_watches '.The main idea: inotify the number of default mo

Recently, when researching the load of Linux system, I have been exposed to some knowledge about CPU information, and share it with you. A lot of things have been learned by analyzing the parameters in the/proc/cpuinfo file.In the Linux operating system, the CPU information is loaded into the Cpuinfo file under the virtual directory/proc in the boot process, and we can view it through Cat/

There's been a lot of threads today. The problem of running out of virtual memoryThe PID of my application is 2558 to see the status at this time:[Email protected]:/proc/2558# cat StatusName:soniaState:s (sleeping)tgid:2558pid:2558ppid:2335tracerpid:0uid:0 0 0 0gid:0 0 0 0fdsize:256groups:0vmpeak:2812816 KBvmsize:2799304 KBvmlck:0 KBvmpin:0 KBvmhwm:799404 KBvmrss:790564 KB physical Memory use, here is 4G physical memory, is no problemvmdata:2721456 KB

if the destination IP of the packet is viewed the same as the source host IP address of the sending request, and this completes the request.For security reasons, the Linux system disables packet forwarding by default. The so-called forwarding is when the host has more than one network card, which receives a packet, according to the destination IP address of the packet sent to another network card, the network card according to the routing table continue to send packets. This is usually the func

Have the Result Set of a Stored Proc Sent to the RSS feed.by Jbrooks 14. December 12:44I wanted to monitor one of the my system from my desk top and from my phone. I found a simple solution whereby I can subscribe to the result set of a stored proc by using RSS. So I can having this feed MS Outlook, my phone or my web browser.First, Visual Studio makes creating an RSS feeds a simple matter that's about 1 pa