How to get the correct classpath for compiling MapReduce jobs on Hadoop 2.2.0 (YARN)?
The yarn command from Hadoop 2 can find it out for you:
yarn classpath
You may add the full path to yarn which is under bin directory of the Hadoop distribution pachage, if it is not in your $PATH.
I would like to open files by open() directly. But how to get a FILE pointer from a file descriptor in C on Linux? And how to do the reverse direction: get a file descriptor from a FILE pointer? Get a FILE pointer from a file descriptor (e.g. fd) in C on Linux: FILE *file…
In C, how to get the hostname of the node? In C, you may use the gethostname function. #include <unistd.h> int gethostname(char *name, size_t namelen); The gethostname() function shall return the standard host name for the current machine. The namelen argument shall specify the size of the array pointed to by the name argument. The…
When we compile some project, it needs older version gcc/g++ version. So how to insall older ones in ubuntu 16? Install older gcc/g++ version sudo apt-get install gcc-4.4 g++-4.4 g++-4.4-multilib gcc-4.4-multilib Set gcc/g++ version to be used automatically sudo update-alternatives –install /usr/bin/gcc gcc /usr/bin/gcc-4.4 50 sudo update-alternatives –install /usr/bin/g++ gcc /usr/bin/g++-4.4 50 You may need…
How to get the full request URL of the page being processed in PHP? If you are sure the request is a http or https one, and the PHP script is executed according to (e.g. by a load balancer or apache reverse proxy) the REQUEST_URI/HTTP_HOST which are set by the client, the PHP script can…
Update on Oct. 9, 2014: You should be aware of the possible security problems of blowfish and it is suggested not to be used. Instead, you may consider ChaCha20 as suggested by Tony Arcieri. To use this with OpenSSH, you need to specify the Ciphers in your .ssh/config files as chacha20-poly1305@openssh.com possibly with another default…
We need more loop devices on Linux than the default number (most commonly 8) some time, such as we are building 12 or more virtual machines on top of xen using loop device backed VBD. In this post, we want to use 32 loops. 1. If loop device is compiled directly in the kernel Pass…