Download ##TOP## And Run Pdf Sequential Number Generator
Inge Offley
I have an application. Suppose it's an invoice service. Each time a user creates an invoice I need to assign the next sequential number (I.e: ISequentialNumberGeneratorRepository.Next(); So essentially the invoice number must be unique despite having several instances of my application running (horizontal scalability is likely in the future).
Traditionally this problem is resolved by using a relational database such as SQL server, PostgreSQL, MySQL, etc. because these systems have the capability to generate sequential unique IDs on inserting a record and returning the generated id as part of the same atomic operation, so they're a perfect fit for a centralised sequential number generator.
So my question is: Is there any available product out there which I could use to generate unique sequential numbers so that I can implement my Next(); repository's method with, and which would work well independently of how many instances of my client invoice application I have?
The only way to guarantee numerical order across a horizontally scaled application without aggregation, is to utilize a central server to assign the numbers(using REST or RPCs or custom network code; not to mention an SQL server, as a side note). Due to concurrency, the application must wait it's turn for the next number and including network usage and delay, this delay limits the scalability of the application, and provides a single point of failure. These risks can be minimized by creating multiple instances of the central server and multiple application pools(You will lose the global sorting ability).
As an alternative, I would recommend the HI/LO Assigning method, combined with batch aggregation. Each instance has a four? digit identifier prefixed to an incrementing number per instance. Schedule an aggregation task on a central(or more than one, for redundancy) server(s) to pickup the data and assign a sequential unique id during aggregation. This process localizes the data(until pickup, which could be scheduled for (100, 500, 1000)? millisecond intervals if needed for coherence; minutes or more ,if not), and provides almost perfect horizontal scaling, with the drawback of increased vertical scaling requirements at the aggregation server(s).
I'm curious though as how to generate sequence numbers for large distributed systems where there is no database. Does anybody have any experience or suggestions of a best practice for achieving sequence number generation in a thread safe manner for multiple clients?
You'll need to differentiate between sequence numbers and unique IDs that are (optionally) loosely sortable by a specific criteria (typically generation time). True sequence numbers imply knowledge of what all other workers have done, and as such require shared state. There is no easy way of doing this in a distributed, high-scale manner. You could look into things like network broadcasts, windowed ranges for each worker, and distributed hash tables for unique worker IDs, but it's a lot of work.
The next 14 or so bits: A per-generator counter, which each generator increments by one for each new ID generated. This ensures that IDs generated at the same moment (same timestamps) do not overlap.
The last 10 or so bits: A unique value for each generator. Using this, we don't need to do any synchronization between generators (which is extremely hard), as all generators produce non-overlapping IDs because of this value.
c) You could generate the IDs on the clients, using just a timestamp and random value. This avoids the need to know all generators, and assign each generator a unique value. On the flip side, such IDs are not guaranteed to be globally unique, they're only very highly likely to be unique. (To collide, one or more generators would have to create the same random value at the exact same time.) Something along the lines of:
Note that many database sequence number implementations (e.g. Oracle) do not guarantee either monotonically increasing, or (even) increasing sequence numbers (on a per "connection" basis). This is because a consecutive batch of sequence numbers gets allocated in "cached" blocks on a per connection basis. This guarantees global uniqueness and maintains adequate speed. But the sequence numbers actually allocated (over time) can be jumbled when there are being allocated by multiple connections!
I have written a simple service which can generate semi-unique non-sequential 64 bit long numbers. It can be deployed on multiple machines for redundancy and scalability. It use ZeroMQ for messaging. For more information on how it works look at github page: zUID
Using a database you can reach 1.000+ increments per second with a single core. It is pretty easy. You can use its own database as backend to generate that number (as it should be its own aggregate, in DDD terms).
Hi everyone! The Auto-Number column as @streety suggested would allow you to number projects in order down your board. The order is based on the order of your items, so if you move items around, the numbers will change. This is intended to keep the numbers in running order per group or for the entire board.
Another option would be to use the Item ID column as referenced in the related thread above. This will work differently as it will generate a unique ID for each item that will not be sequential. The numbers will, however, stick with your items even if they are moved
I add my vote to the request. This would be a very useful feature for us as well. We are considering to move the CRM functionalities from SAP to Monday, in order to have a more effective workflow. We track Porposals and each of them need to have a unique sequential (in the FY) identifier. It would be great if Monday could automatically generate a new sequential identifier each time we add one, so to be sure to avoid duplicates.
Still busy creating a standard template to be used in our design office. One of the issues I am running into is to try and standardize any entry as much as possible, using dropdowns or lists. Most of this I have been able to sort out and link this to a Form driven in the background with a number of Rules to give me the information we want in our iProperties.
However, the one last bugbear I have is my Part Number - our part number consists of a number of fields that describes a level in the assembly down to single part level. I have been able to get the descriptor part done to my satisfaction, but now I need to generate a sequential 4 digit number. I can see that somewhere there needs to be a database to ensure the numbers stay unique and preferably linked to the descriptors that makes up the rest of the part number.
I'm looking to introduce unique sequential numbering into a SharePoint List - currently we ID items via something we call a BSS Number, if you look at my screenshot below you'll see we have a 'BSS.No' column, with BSS-001 for one item , BSS-002 for the next, and so forth.
Currently, we enter these BSS numbers manually into the a 'Single Line of Text' column when we add a new item to this list, however this is kind of inneficient as we first have to go through the list to find the newest item so we can see what the last number used was, so going forward I'd like it to try and automate it so when a new item is added, the BSS number would just increment upwards 1 from the last entered BSS number (IE if the last item had a BSS of BSS-50, then the next item would automatically be assigned BSS-051), however I'm not sure how to do this. I know SharePoint Lists have a native ID field, however we'd prefer to use our own identification method as we've already been using the BSS numbers for identification for quite a while, and it'd be a bit of a pain to switch over, plus I'm not sure how accurate the native ID numbers would be.
Hi @Guero , strangely I answered a very similar question in my own company yesterday so the steps I gave then with the incrementing number starting at 100000 are below and the screenshots further down. I hope it helps but if it's not quite what you want do come back with any questions.
I've also got a separate list called CurrentIncrement with the title column just having a value of "Current value". There is also a number column with no decimal points called Inc with a default value of 100000.
I was able to use your solution for incremental numbers, however the incremented number only works on the very first entry in my list (it would be your CropLocation list). Something that is different than what appears in your screenshots is "Title" is a required field and I've added that and I'm thinking that shouldn't be the issue. Any help would be greatly appreciated.
Is there any sample code out there implementing a sequential order number generator? I'm particularly looking for code which could create a custom table on demand and then load and save a single record.
I have implemented a sequential order number generator using code in the link you gave me. This will serve our purpose for the time being (migrating from TeaCommerce). Maybe one day we will have enough business for this generator to become a performance bottleneck, and will then review and maybe revert to Vendr's built in solution :-)
These numbers are updated when you sort them with your data. The sequence might be interrupted if you add, move, or delete rows. You can manually update the numbering by selecting two numbers that are in the right sequence, and then dragging the fill handle to the end of the numbered range.
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