These are a few Time To mechanisms that can have some light shun upon them as they can be quite useful to a developer. I will be answering them below in an attempt to explain what they can be used for and why on the #platform.
Time To Mechanisms (Attributes of Metadata)
Any data that is shared between #signs can go through several mechanisms. Some of these mechanisms include TTR (Time To Refresh), TTL (Time To Live), and TTB (Time To Birth).
Time To Refresh
TTR, which is an attribute of the metadata of a shared key, accepts an integer value which represents seconds. The subsequent refresh happens based on the given value: for example, if the set TTR value is 86400, then the refresh happens once in a day (there are 86,400 seconds in a day). Another very important attribute of the metadata is CCD (Cascade Delete), which is a boolean variable (a variable that accepts true or false values). For those who are well versed in SQL and database management, you will already have some understanding of what CCD does and how it functions.
If the CCD value is set as true when the sender deletes their original key, the cached key gets deleted on both the sender’s server and the recipient’s server. Correspondingly, if the CCD value is false when the sender deletes their original key, the cached key gets deleted on only the sender’s server and remains cached on the recipient’s server. But why is this useful? CCD is used to avoid unnecessary network calls. As an example: if #alice is in need of #bob’s phone number, she does not need to make a request from her server to #bob’s server to find it, but rather needs only to search locally on her device to find the phone number.
Let’s consider a similar example: #alice shares her phone number with her friends #bob and #john. A few months later, however, #alice purchases a new phone plan, resulting in a new phone number. If #alice has her #sign’s TTR variable set to true, once she updates her old phone number to match her new one, this updated value will also be reflected on #bob and #john’s devices. #alice also has the ability to set a specific time, in seconds, for when the new phone number will be cascaded on shared servers (this is TTB, which is described later). This can be 10 minutes, a day, or whatever specific amount of time she defines.
This function can be quite handy, especially if someone is constantly updating values on their server. This prevents a high density of calls and requests whenever someone wishes to see what new values exist on a shared server.
Time To Live
TTL (Time To Live) is quite self-explanatory: it defines how long data will live on a server. Anyone with an #sign has the ability to upload information on their server and define how long it stays on the server before it is automatically deleted. If #alice wishes to share her summer vacation getaway location as her current location, she has the option to share that summer vacation location for as long as she plans on being there!
To really take advantage of a mechanism like this, developers can combine it with other Time To commands to make life for themselves and those they share their information with easier. Say for instance Alice lives in sunny San Francisco, and owns a vacation home in Spain. With mechanisms such as Time To Refresh and Time To Live, Alice has the ability of travelling to her vacation home for several weeks, uploading her current location as Spain, and setting that information to live on her server for the several weeks that she will be staying at that location.
Time To Birth
Another Time To mechanism that is utilized within the #protocol is the Time To Birth mechanism. This mechanism allows individuals to upload information to their secondary server and have it become activated after a specified amount of time, in seconds. During the time that the data is not ‘active’, any recipients of this information will see the ‘null’ value in place until the activation has occurred.
For example, if #alice wishes to upload a web URL of her personal website after she has completed it, she can simply specify that the URL value can be uploaded to her secondary in exactly 1 days’ time. Until the value is updated a day later, #bob can only see that her website URL is ‘null’.
Related
When doing scanning with passive RFID tags, you can set the SESSION to '2' in order for the tag state of 'B' to persist for "an indefinite amount of time" even when it is not being energized by the scanner, according to the standards. Your tag will then not be visible to the scanner until this indefinite amount of time expires.
My question is, does anyone have any idea what the maximum amount of time is for RFID tags? I'm sure it's different for different tag manufacturers , etc. However, are we talking seconds, minutes, hours, or even days? I don't want to keep seeing the same tags over and over again while doing a scan in the storeroom, but at the same time, I don't want the tag to be hidden if they need to be scanned again at a later time.
The answer is: it depends. Please note that the standard says 'indefinite when powered'. When powered, it is really indefinite. When not powered, the standard defines it is longer than 5 seconds. For most modern tags, it is typically less than 30s, of course depending on environment conditions.
About the definition of 'powered': please note that this power can originate from any RFID reader, not only the one you are using to interrogate the tags with. Or any other radio device that transmits at the same frequency.
To circumvent this, you can use a SELECT statement to revert the session flag back from B to A.
I need to measure the response time for a file export using Trueclient protocol in loadrunner.After i click on the export button the file will get downloaded. But i am not able to measure the time for the download accurately.
Pull that data from the HTTP request log, which will show the download request, and, if the w3c time-taken value is included in the log, the time required to fulfill the download.
You can process the log at the end of the test for the response time data. If you need to, you cam import a set of datapoints into analysis for representation with the rest of your data. You might want to consider a normalized value for your download, instead of a raw response time. I imagine that the files are of different sizes, so naturally they will have different download times. However, if you divide download bytes with time (in seconds), then you will have a normalized measurement of bytes per second which then allows you to compare one download to the next for consistent operation.
Also, keep in mind that since you are downloading a file, writing to a local disk, for (presumably) multiple users on a host, you will face the risk of turning your local file system into a bottleneck. You can see this same effect if you turn up logging on all users to the highest level and run your test. The wait for lock and wait for write, plus the actual writing of data, becomes a drag anchor to the performance of your virtual user. This is why the recommended log level is "log on error" or send the error to the output window of the controller via lr_output_message() or lr_vuser_status_message(). Consider a control load generator of the same hardware definition as the others with only a single virtual user of this type on it. If the control group and global group degrade together then you have an app issue. If your control user does not degrade, but your other users do, then you have a test bed induced influence on your results.
These are all issues independent of the tool you are using for the test.
I know that AAD application ID is unique in one directory (tenant). It is a guid and apparently should be unique in whole world but collisions may be. The question is: does Azure while generation AAD application ID validate whether it is unique across all others directories or not?
If you look at the official document for application property you would know application id is
The unique identifier for the application that is assigned to an
application by Azure AD. Not nullable. Read-only
How Azure Application Id Generated Uniquely:
Application Id (GUID) break down like this:
60 bits of timestamp,
48 bits of computer identifier,
14 bits of uniquifier, and
six bits are fixed
Total of 128 bits.
The goal of this algorithm is to use the combination of time and location (“space-time coordinates” for the relativity geeks out there) as the uniqueness key.
However, there’s a possibility that, for example, two GUIDs are generated in rapid succession from the same machine, so close to each other in time that the timestamp would be the same. That’s where the uniquifier comes in.
When time appears to have stood still (if two requests for a GUID are made in rapid succession) or gone backward (if the system clock is set to a new time earlier than what it was), the uniquifier is incremented so that GUIDs generated from the “second time it was five o’clock” don’t collide with those generated “the first time it was five o’clock”.
Once you see how it all works, it’s clear that you can’t just throw away part of the GUID since all the parts (well, except for the fixed parts) work together to establish the uniqueness. This is how all that works.
Note: Even sometimes network address also considered for GUID.
Say we have an A REC that points to IP x of our LB for one of our services. It has a TTL of 3600s. But... what it should have been was a C NAME that points to a A REC for a VIP. It's already in production and has about 10 services that calls the new A REC comprising of ~100 machines. If the A REC is deleted and a new C NAME is created with the same name and points to a new A REC, will the consumers notice this change? Is there a chance that the callers would time out?
I'd assume with the amount of machines some are bound to be impacted. If I set the TTL to 5 hours would there be a better chance of no one noticing?
So my question is, how do I swap an A REC for a C NAME without consumers of our service noticing?
Would it matter if the record is for use inside the network only vs available to the public?
I ask because we will need to load balance across data centers soon, and we have some records that are stuck pointing to an IP.
It would be nice to have an explanation of how the DNS system would behave in this scenario. Thanks.
Let's assume that you have a name foo.example.org that has nothing except an A record with the IPv4 address 192.0.2.1 and a 3600 second TTL. Anyone who looks up foo.example.org will get that A record, and remember it for an hour before they go and ask your name server for fresher information.
Then assume you change things so that foo.example.org has a CNAME record pointing at bar.example.net, which in turn has an A record holding the address 192.0.2.1. Anyone who looks up the name foo.example.org for the first time will get the CNAME, proceed to look up bar.example.net, and get the A record from there.
The only complication is that anyone who looked up foo.example.org during the 3600 seconds immediately before you change to the CNAME chain took effect will remember the direct lookup, and thus not see the new information until the TTL expires. So for up to an hour after you do the change, some people may still see the old information. So to keep the change transparent to users, make sure that the old information (the old IP address) still works for at least one full TTL period after you make a change.
This is not in any way special for changing from A to CNAME. No matter what you change, there will be a full TTL period during which clients can legitimately get the old info. That's just how DNS works.
On top of that, of course, there are clients and caching servers that don't pay as much attention to the TTL value as they should, but that's a whole different thing.
I would like to know if it is possible to do a full statement (between a date range) through ISO 8583, I have seen ATMs which do full statements and was wondering what method they used. I know balance inquiry and mini statements are possible on a POS devise over 8583.
If it is possible does anyone have an information on the structure of the message, ideally for FLexcube.
we did something similar to that back in 1999 in one of the banks, where we would send the statement data in one of the generic private use fields, where it would allow the format ANS 999
but that means you are either to restrict the data to less than 999 characters, or to split the data on multiple messages. and have a multi legged transaction.
you would have the following flow
Customer request for statement on ATM
ATM sends NDC/D912 message to ATM Switch
ATM Switch look up account number after authenticating the card and forward the request to Core Banking Application
Core banking application would generate the statement and format it according to predesigned template and send the statement data into a generic field (say 72)
ATM Switch collects the data and formats it to NDC or D912 format where the statement data is tagged to statement printer (in NDC it is a field called q and the value should be ‘8’ - Print on statement printer only)
and on the field r place the preformatted data
however, it is not a good practice to do so, since we have faster means to generate a statement and send to email or internet banking. but this is the bank's preference anyways.
It depends upon implementation,
I had implemented NCR central switch, where I incorporate initial checking stuffs in the Central application itself rather than passing everything to Auth Host.
My implementation.
ATM Sends (NCD) the transaction requests based on State Machine setup in ATM to Central Application.
Central does basic checkings such as Validity of BIN (initial 6 digit of card no.) and also checks if the requested amount of cash is available in the ATM etc.
The the Central App sends the packet (ISO8583/BASE24) is sent to the Acquirer for further processing.
Acquires Sends it to CA and then it goes to Issuer for Approval.
Hope this helps.
The mini-statement is not part of ISO 8583 (or MVA). It is usually implemented as a proprietary extension. Hence you need to go to an ATM owned by your bank, or, is part of a consortium of banks that share an ATM infrastructure with your bank.
We implemented mini-statements in our ISO-8583 specification utilizing a $0.00 0200 (DE003 = 91xxxx) message and the statement data coming back from the host on DE125 on both Connex and Base24 and then modified our stateful loads to print the data at the ATM.
Though full statements fell out of use years ago so we removed it to just be mini-statements now utilizing the receipt printer vs. full page statements. There is a limited number of entries and not all host support it but it is used today on NCR & Diebold ATMs. I've personally participated in the testing in getting it to work on Base24 and Postilion.
The mini-statement data we do print is 40 characters per line and prints about 10 transactions I believe.