General description – what the hell will we try to do here: When you find yourself chasing memory leaks, or Heisenbugs for a long time chances are you will have a huge debug log. If the disk gets full and you need only the logs at the end when the problem raises it’s ugly head, use the technique described here.   The technique involves: closing the file handle where the process writes the logs currently – int creat(const char *path, mode_t mode); creating a new…Continue Reading “Hot-swapping a log file on a running process w/ GDB w/o stopping it”

UPDATE: Nodejs driver 3.X.X introduces a bunch of incompatible changes compared to 2.X.X versions. For one, you will need to use projections instead of field selectors. Also, you will need to pass results from functions by calling callback() which will pass the variable to the caller. function GetTenantIDFromName(exp, db){   let rxPtt = new RegExp(exp, 'gi');   let tID = db.collection('Tenant')     .find({ "Name": { $regex: rxPtt }},{"_id":1})     .toArray();     return tID; } // possible way to call this let tID = GetTenantIDFromName(tenant, db); tID.then(function(polluterTenantId){   console.log(polluterTenantId); }); function GetTenantIDFromName2(exp,…Continue Reading “On: some gotchas working with mongoDB”

Thiel was born in Germany, went to US as a young boy, is a Stanford philosophy BA, VC who was involved in Y Combinator, Paypal, has invested in Tesla and SpaceX, early investor in FB. He excelled in math as a youth and was a Valedictorian in his high-school graduation. Currently @ almost 3 billion net worth. The ideas outlined below are heavily paraphrased and modified.

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Sometimes you find yourself cheeping out an giving not enough space on you virtualbox host machine. Self-sabotage, masochism – who knows the reasons that rule the decision of not assigning the default 8GBs of space that is ALLOCATED AS NEEDED. Sometimes you give it 32 gigs, and finding that all of a sudden that is not enough… In any case you have the privilege to reverse some mistakes of planing and this is one of them reversible types. Since software is constructed following the principle…Continue Reading “How To: Increase the Size of Red Hat / CentOS / Fedora VirtualBox guest host … and some LVM usage stuff”

The port numbers are divided into three ranges: the well-known ports, the registered ports, and the dynamic / private ports (a subset of which are used for ephemeral port assignment). Seeing 127.0.0.1:55555 being used for local application w/ static port assignment is not “correct” (it’s not really “incorrect” either, hence quotation marks) 4 2 reasons.

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I consider certifications as the ultimate learning tools. That is quite frankly all. A learning experience that gives you skills, understanding, knowledge, but not entitlement or guarantees. Well, the above is not a factual statement, it’s an expression of attitude. In it, I consciously choose to be empirically incorrect – even wrong (I will explain how in a short while) – while focusing, laser-sharp, on the thing that is important. It is an attitudinal heuristic or a value judgement, if you will. And in this…Continue Reading “On: Certifications. In IT and in general”

Doxygen allows the generation of documentation from source code files for various languages: C/C++, C#, JAVA, Python and others. This is a short document on how to work with it, serving as a reminder for me and maybe helping others at the same time.

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