Probably common sense, but this statistically supports the most common roll of the dice. Of course, this assumes physical normalcy of the die, not loaded, etc. 🙂 [root@cmhlcanlyodb01 ~]# cat rand.py import random d = dict() for i in range(1,100001):…
CRC check on gzip files in HDFS
I am sure there is a more elegant way to do this, but I wanted it done quickly. We had a few files that threw exceptions about the end of the file being reached (CRC failure) for external files underlying…
Simple network test with client and server
This simple network trace shows the essential elements of a network interaction between a client and a server. For our test, we use the following for the client… import sys, socket, time remote_ip = socket.gethostbyname(socket.gethostname()) s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) #s.setsockopt(socket.IPPROTO_TCP,…
Spoofed IP network behaviour
In this case, we spoof the IP of our client to 192.168.1.101. When we do this, and send only a SYN packet to the server, we see the SYN on the client… [root@cmhlcarchapp02 ~]# python spoof.py 1 09:37:52.469226 IP 192.168.1.101.49999…
PowerShell for *nix people
PowerShell is becoming (has become) the replacement for VBScript on Microsoft operating systems. It is a fairly robust scripting language that I think most administrators will be happy to see. If you have a supported Microsoft operating system (i.e., not…
Loading compressed data into MySQL in batches from python
We used what is below to load 12 million rows into a laptop MySQL database in 48 minutes. I’m sure it can be improved, but we were initially OK with this result. import gzip, os, sys, string, mysql.connector fd =…