A simple insert query turned into a silent performance killer. Our frontend pings our server every few minutes to track device activity. Each ping attempts to insert a row into a DevicePingDaily table, which has a unique constraint on (device_id, date) to ensure only one record per device per day. In Django, the logic looked like this: try: DevicePingDaily.objects.create(device=device, date=today) except IntegrityError: pass It seemed harmless. But as traffic grew, latency spiked and API timeouts increased. Observability tools quickly pointed to the culprit:

I have a project where multiple users will map multiple layers using multiple devices, and I would like records to have IDs that are digestible to the human brain for referencing purposes. I have attempted to implement a code presented in this thread for sequential unique ids per device/layer in a field called "fn_name": (substr(@device_id , 1, 1))||'_ART'|| (coalesce(maximum(to_int(substr(fid,strpos(fid,'_ART')+3)) ,filter:=substr(fid,0,strpos(fid,'_ART')-1)=(substr(@device_id , 1, 1))),0)+1) At first I get an error, Could not calculate aggregate for: to_int(substr(ID, strpos(ID, '_ART')+3,NULL))(Field 'ID' not found), which is resolved when I create an "ID" field. Then, the initial unique id gives what I want, something like c_FPT1, but every new record afterwards produces the exact same id; the numbers do not increase. The following code is the closest I have gotten, based on another old thread: (substr(@device_id , 1, 1))||'_FPT'||LPAD(count(@device_id=@device_id),3,0) Here, the first part of the code, (substr(@device_id , 1, 1)), produces the first letter of the device_id, a naming variable I've added in QField for each device, in this case a device name starting with c. FPT is short for the layer, in this case FeaturePoint. Then follows a count function. The result are IDs like: c_FPT001, c_FPT002, c_FPT003, c_FPT004... The first and most important problem is that the initial id appears as c_FPT000 when the record is being added, but saves as c_FPT001. The second record appears as c_FPT001 but saves as c_FPT002, and so on. This is a little more than an annoyance, it could confuse the operators especially when some written notes are being taken as the record is being made. Additionally I would eventually like photos taken under the record to be named partially after the fn_name field as per this thread, but for that fn_name cannot change after the photo is created. The second problem is that I am not positive the ids will be unique, the principle concern in the original thread. The third is most minor, I would like numbering to go from 1 to infinite and do away with leading zeros. I could determine how to do this but I would like to implement the first code above correctly to solve problems 1 and 2. ############# I have also tried other options: The code presented here, if(count(@layer_id)=0,1,maximum(“nummering”)+1), does not seem to work with a text string (?). The first record reads correctly but following records are empty. I have tried the codes presented in this thread, both as default expression in the ID field, as well as within the fn_name code, but the resulting fn_name field is either empty or does not increase sequentially or at all. Several threads mention use of @row_number or $id but these either produce null fields or do not seem to produce sequential numbering per layers from 1-infinite. These may also be designed to work with an integer field (?) There was apparently once a Sort and Number plugin but it seems to be depreciated. There is now a function in QGIS called Add Autoincremental Field, but it creates a whole new layer and only seems to work after data are already entered. I am using QGIS version 3.40.3-Bratislava with geopackaged layers.

Danke! Ich habe mir da von ChatGPT helfen lassen. Wohl nicht der beste Helfer für sowas...

Capgo before 12.128.2 contains a rate limit bypass vulnerability in the channel_self endpoint that allows attackers to circumvent rate limiting by rotating the user-controlled device_id parameter. Attackers can send multiple requests per second by changing device_id values to flood the channel_devices table and cause database exhaustion.

librenms is a community-based GPL-licensed network monitoring system. Affected versions are subject to a stored XSS on the parameters (Replace $DEVICE_ID with your specific $DEVICE_ID value):`/device/$DEVICE_ID/edit` -> param: display. Librenms versions up to 24.11.0 allow remote attackers to inject malicious scripts. When a user views or interacts with the page …

前回：msyksphinz.hatenablog.com github.com RISC-V IOMMUの構成について、概略をざっくり理解するためのメモ。 何回か読もうとして挫折してきたので、もう一度ちゃんと読んでみようと思う。 デバイスコンテキストの場所を特定するプロセス device_idを使ってトランザクションのDevice-contextを見つけるプロセスは以下の通りである： a を dd...

I asked a TON of comics people what their TOP 3 Indie Com...

Fukushima City Education Board is fortifying security in schools by adopting Cybertrust's Device ID service, ensuring a safe environment for teaching staff.