Hi, Instead of using a collection, consider making label a clustered column.
With this each request will essentially append a column (label) to the partition. To get all labels would be a simple query select label from table where partitionkey = "value". In general , read + update of a column is an anti pattern in cassandra - which is what you are doing. What I suggesting above is appending more columns and not updating existing columns. regards regards On Sat, Nov 12, 2016 at 2:34 AM, Ali Akhtar <ali.rac...@gmail.com> wrote: > I have a table where each record contains a list<string> of labels. > > I have an endpoint which responds to new labels being added to a record by > the user. > > Consider the following scenario: > > - Record X, labels = [] > - User selects 2 labels, clicks a button, and 2 http requests are > generated. > - The server receives request for Label 1 and Label 2 at the same time. > - Both requests see the labels as empty, add 1 label to the collection, > and send it. > - Record state as label 1 request sees it: [1], as label 2 sees it: [2] > > How will the above conflict be resolved? What can I do so I end up with > [1, 2] instead of either [1] or [2] after both requests have been processed? > -- http://khangaonkar.blogspot.com/
