What’s with these pointless empty log files? And why does the csvlog mode create plaintext ones too?

I’ve been fighting for days now just to get god damn logging set up. I’ve had to write a ton of code manually because PG doesn’t provide any automated mechanism to do this, for some reason, nor even tells you anything, beyond this: https://www.postgresql.org/docs/12/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-CSVLOG

I have:

  1. Set up the postgres_log table exactly like it says on that page.
  2. Set up my postgresql.conf like this (also as it says on the page, except it only describes it vaguely and lets me find out everything on my own):
log_destination = 'csvlog' logging_collector = on log_directory = 'C:\pglogs' # Yes, I requires double \ chars or else it removes them entirely... log_filename = 'PG_%Y-%m-%d_%H;%M;%S' log_rotation_age = 1min log_rotation_size = 0 log_truncate_on_rotation = on 
  1. Coded my own mechanism to constantly go through C:\pglogs for any .csv file, skipping any ones that PG reports are already in use with pg_current_logfile, feed them into PG’s table and then delete the file. This took me a huge amount of time and effort and not a word about it was mentioned in that "manual".

Questions:

  1. PostgreSQL creates both PG_2020-09-20_00;56;19.csv (in CSV format) and PG_2020-09-20_00;56;19 (in plaintext format) files. I obviously don’t want the extensionless files. Why are they created?
  2. Every minute (as specified) PG creates new log files, even if there’s nothing new to log. This results in an endless stream of empty log files (which my custom script goes through, "imports" and then deletes). How do I tell PG to stop doing that? It seems like pointless wear & tear on my disk to make empty files which are just deleted seconds later by my ever-running script.
  3. Why isn’t all of this automated? Why do I have to spend so much time to manually cobble together a solution to import the CSV files back into PG? In fact, why are they dumped to CSV files in the first place? Why doesn’t PG have the ability to directly log into that database table? It seems like a pointless exercise to dump CSV files which are only going to be COPYied back into the database and then deleted.

With respect to differential privacy what should be the qlobal sensitivity for regression in non interactive mode?

I need to make a dataset differentially private on which regression, which in more general sense could be extended to learning any model, is to be performed. I need to calculate the global sensitivity for adding noise. How do I calculate global sensitivity in such cases.

Certbot challenge error 404 in webroot mode

This web site runs under Apache on Windows. I installed Windows certbot client and ran it as suggested on its homepage, in webroot mode, since the web site cannot be stopped. This is what it reported:

C:\WWW\somedomain>certbot certonly --webroot Saving debug log to C:\Certbot\log\letsencrypt.log Plugins selected: Authenticator webroot, Installer None Please enter in your domain name(s) (comma and/or space separated)  (Enter 'c' to cancel): somedomain.com Obtaining a new certificate Performing the following challenges: http-01 challenge for somedomain.com Input the webroot for somedomain.com: (Enter 'c' to cancel): c:\www\somedomain Waiting for verification... ←[31mChallenge failed for domain somedomain.com←[0m http-01 challenge for somedomain.com Cleaning up challenges ←[31mSome challenges have failed.←[0m ←[1m IMPORTANT NOTES: ←[0m - The following errors were reported by the server:     Domain: somedomain.com    Type:   unauthorized    Detail: Invalid response from    http://somedomain.com/.well-known/acme-challenge/UIWHcmUsNd_4itYD5IWMLSuldIF4yzd2m9mpSH4W7a0    [2**.1**.1**.2**]: "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML    2.0//EN\">\n<html><head>\n<title>404 Not    Found</title>\n</head><body>\n<h1>Not Found</h1>\n<p"     To fix these errors, please make sure that your domain name was    entered correctly and the DNS A/AAAA record(s) for that domain    contain(s) the right IP address. 

The certbot server does query the right IP address, so the DNS record is working fine. I suspect that it may not be creating the challenge folder/file. I tried creating the above URL manually and querying it in a browser from elsewhere, and it is being served fine. Any ideas what is missing for certbot? Keep in mind that somedomain.com is only used here for example.

How can a CPU be busy during DMA access with burst mode transfer

During burst mode in a DMA access, the DMAC has control over the bus for the whole transfer session which includes DATA PREPARATION time as well as DATA transfer time, after the transfer is over, the DMA relinquish the system bus. So in the mean time, the cpu can neither fetch any instruction from the MAIN MEMORY, nor it can fetch any operand, it can atmost complete the instruction it was executing before if that don’t include the use of system bus. In the book I have seen as cpu busy percent is given by

Data preparation time/(data prep time + data transfer time) How can the cpu be busy during the data preparation time when the bus is not with it. This can be the concept behind CYCLE STEAL mode, since it gains the bus only during data transfer, but how during burst mode??

Can airplane mode provide a “free” I.P. masking service?

My email service always logs the I.P. address of the device from which the email account was accessed(or an unsuccessful login attempt was made) for security reasons.

While going through the list once, I found that I had quite a few different I.P. addresses on that list, most of which were successful logins.

After some thinking, I remembered that I have been putting my phone on airplane mode quite often(which I still do, due to the internet connection dropping quite often at my home). I thought that this process was changing my I.P. address.

So, right now I checked for it again, and found that the last 2 octets of the IPv4 address changed everytime I switched ON(and then OFF) the airplane mode.

What is more interesting is the fact that the location of the device(checked on some online sites) was found to be oscillating between my city and a neighbouring satellite city.

So, my question is that, could this method, if used multiple times a day, act as a "free" I.P. masking service?

Effect of Firefox’s “Responsive Design Mode” on the browser’s fingerprint

Today I switched ON the "Responsive Design Mode" under the "Web Developer" Section of the Firefox menu, and from the dropdown menu selected "iPhone X/XS iOS 12".

So now every webpage I visited was being sent the request that the screen size of my device was "375×812".

My question is that, can this method enhance my protection against browser fingerprinting(assuming I also take some other precautions)? Because the websites now wouldn’t be able to know my original aspect ratio/screen resolution, and above 2 iPhones are quite common too(I am using a laptop).

I earlier tried to scale the Firefox window to nearly the aspect ratio of a mobile phone, but that didn’t make any differnce at all.

Note:

(i) In the context of this question my adversaries are only the companies and their websites,and not the Governments & ISPs.

(ii) I am just asking about the effect of this method on my browser’s fingerprint, that is, whether it will increase or decrease the fingerprint. Be advised: I am not using this as the only method.

(iii) Firefox version: 78.0.2

(iv) OS: some linux distro.

Single user mode looses connection

So just a quick background, we are trying to update the database design, in a production environment. But we want to be sure, no users try to login during that time. So we started looking into single user mode, but that gave us some trouble, sometimes we would lose the connection in the middle of the update. So we setup a test environment to replicate the behavior.

We are using Microsoft SQL server 2017, with the AdventureWorks2017 database to replicate the issue. On the database we have turned off Auto close and Auto Update Statistics Asynchronously

If we then have two connections to the server, using the master database. Tell one of them to run this script

USE MASTER SET DEADLOCK_PRIORITY HIGH ALTER DATABASE [AdventureWorks2017] SET SINGLE_USER WITH ROLLBACK IMMEDIATE GO  DECLARE @kill varchar(max) = ''; SELECT @kill = @kill + 'KILL ' + CONVERT(varchar(10), spid) + '; ' FROM master..sysprocesses  WHERE spid > 50 AND dbid = DB_ID('AdventureWorks2017') EXEC(@kill);  USE AdventureWorks2017 GO  DECLARE @cnt INT = 0; WHILE @cnt < 10000 BEGIN   SELECT TOP 1000 * from Person.Person;    SET @cnt = @cnt + 1; end; 

And then on the other repeatedly run

SELECT TOP 1000 * FROM AdventureWorks2017.Person.Person; GO; 

At some point the first script stops working, and complains with an error

Database ‘AdventureWorks2017’ is already open and can only have one user at a time.

But to our understanding, this should not happen cause it still has the connection. Note this doesn’t happen all the time. But it’s still fairly consistent.

Is there anything that we are missing, or can this be an issue with the SQL server?

Can a Solarian’s ability to enter a Stellar Mode take into consideration conditions affecting her?

I know there is GM discretion allowed as to the situations affecting a Solarian’s ability to enter a Stellar Mode, but I would like other GMs opinions on this situation.

RAW seem to generally require that the Solarian be "in combat" and facing a significant threat. In fact, the description specifically says that:

you must be facing a significant enemy (see page 242).

Description of Significant Enemy:

…a creature with a CR less than or equal to your character level – 4 is not a significant enemy

So… nowhere does it give consideration as to the Solarian’s personal situation.

In a hypothetical situation even a lowly CR-1 creature would present a dire threat to a Paralyzed 6th level Solarian, but she would not be permitted to enter Stellar Mode and become attuned, to use her Corona Revelation as a defense because of the low CR rating of the enemy.

In our example situation, the party encountered a group of Ghoul Soldiers who managed to paralyze the Solarian via bite. Combat moved into the next room, leaving the Solarian alone and still paralyzed (for 2 more rounds). I presumed the Solarian’s Stellar Mode ended because there was no current threat to her, and stated such. She argued that the state of paralyzation itself constituted a threat and/or the fact that I still had her in "melee round" mode meant she was still "in combat" (she wanted to become fully attuned so she could jump back in the fight if/when released from paralyzation). I ruled that it must be a threat from an enemy and that her Stellar Mode ended, but she was still in "melee mode" so I could track the rounds of her paralyzation; she was unhappy with this decision.