When a Linux system crashes (usually because of a driver issue), you should make sure at least it restarts. These are the lines you should add to /etc/sysctl.conf: # Reboot time(s) after panic kernel.panic = 20 # Panic if a hung task was found kernel.hung_task_panic = 1 # Setup timeout for hung tasks to 30 seconds kernel.hung_task_timeout_secs = 30
Hi everyone, During the last years, I launched the javacint google group which now has grown out to be a good community of professionnals working around the Cinterion (java enabled) chips. I also created a TC65 development document. And all the questions and feedbacks you gave me on the development around these chips helped me a lot to improve (what was) my document and (what was) my FAQ. You helped me so much indeed that I believe this content should know be open to everyone to modify. That’s why I created the javacint wiki. ...
You might have noticed for xrdp on Debian (but quite possibly with a lot of other Linux tools and other Linux distributions) the user limits (described in /etc/security/limits.conf) are not enforced. Which meant in my case that any session open with xrdp was opened with a max number of open files (nofile) set to 1024. To fix this, edit the file /etc/pam.d/common-session and add the following line: session required pam_limits.so
This is a personal reminder post. The easiest attack one can perform on a web server is opening all the connections and do nothing with it. iptables fortunately has a “connlimit” module to avoid this. If you’re using ufw like me you will want to keep your good integration with it. In the `/etc/ufw/before.rules file, after these lines: # Don't delete these required lines, otherwise there will be errors *filter :ufw-before-input - [:] :ufw-before-output - [:] :ufw-before-forward - [:] :ufw-not-local - [:] # End of required lines You can add this to limit the number of concurrent connections: ...
One of the biggest issue with distributed database is to find the right model to store your data. On a recent project, I decided to use a registry model. The registry idea The idea behind writing a registry is to have an easy way to both store and view data. For a given device that has a {UUID} id: I will access “/device/{UUID}/”. Any properties will be stored in “/device/{UUID}/properties/”. Deletion of the device will delete all the contents this device contains. Classical column-families to index data The problem comes with the data we need to index. We can store everything in a registry manner like having a path “/device/by-owner/{UUID}”:["{UUID1}","{UUID2}"]. But it’s just easier to use cassandra secondary indexes have each property of each entity written to the indexed columns of the column family. ...
This is now on the wiki.
Changes are: Removed references to the FAQ and the M2MP protocol. Added explanations on how to handle the deployment of multiple versions. Added a quick note on how to use the jazzlib library for gzip compression. The TC65Dev now is on the wiki.
I have a bad addiction to movies. I keep watching them even if most of them just look alike. Here are some (recent) movies that I found uncommonly great: Perfect sense Youth in revolt Lars and the real girl Jesus henry christ
The world is full of good surprises, and TINC is definitely one of them. Are you running a distributed system across multiple datacenters? Perhaps you’re using Cassandra or another distributed database? TINC is the networking solution you’ve been looking for. TINC creates a secure, decentralized virtual private network that automatically establishes a fully meshed topology between your nodes. What makes TINC stand out: Zero single points of failure Automatic mesh routing around NAT and firewalls Military-grade encryption Remarkably simple setup I followed these setup instructions and was impressed by how smoothly everything worked - no debugging or log diving required. For anyone managing distributed systems, TINC is a game-changer. ...
This has moved to the javacint wiki