When I call graph.tx() for TinkerGraph I get exception that graph does not support transactions. But how can I check if graph supports them or not?
You can use GraphFeatures to determine that:
graph.features().graph().supportsTransactions()
which will return true if transactions are supported. You can read more about GraphFeatures here and more about transactions here.
graph.features().graph().supportsTransactions()
Related
I am working on an orchestration layer Microservice where I need to call a few APIs of different microservices in parallel. For that I am making use of subscribeOn(Schedulers.parallel) and subscribing to each response in Mono.zip. For example:
Mono<A> a = service1.api().subscribeOn(Schedulers.parallel());
Mono<B> b = service2.api().subscribeOn(Schedulers.parallel());
Mono<C> c = service3.api().subscribeOn(Schedulers.parallel());
return Mono.zip(a,b,c);
Now AFAIK, this zip will fail if any of the a, b OR c completes with an error. Assume that something went wrong in the third call, I want to handle this case in such a way that any operation done by service1.api() and service2.api() could be reverted, i.e. rolled-back like a transaction.
I apologize for any wrong statement I've made as I am a bit new in Spring WebFlux. Thanks for all the help in advance.
I believe there is no such provision to rollback individual calls. You can make use of Mono.zipDelayError to let complete the valid calls except the one which could fail. After that, on error return you can go for individual transaction rollback with explicitly implementing the same.
I am using C# to call BAPI to communicate with SAP. I am new to this topic so I want to clarify some of the concept.
Q1: If I call BAPI_GOODSMVT_CREATE, should I check RETURN table or MAT_DOC field of items table to see whether it is succeed or failed?
Q2: If it is failed, need I call BAPI_TRANSACTION_ROLLBACK, or just ignore it(because without BAPI_TRANSACTION_COMMIT, data will not be saved)?
Q3: I found sometimes, even if there is error message, if I continue call BAPI_TRANSACTION_COMMIT, the data will be saved. But sometimes it won't.
Thanks in advance.
Check RETURN table. If it's OK, issue a BAPI_TRANSACTION_COMMIT with the WAIT flag. If it's not OK, issue a BAPI_TRANSACTION_ROLLBACK.
Check RETURN from BAPI_TRANSACTION_COMMIT as there may be errors there as well (for example a database update issue).
Ad Q1 In that particular case I'd rather check if material document number is returned in MAT_DOC. This way you don't rely on return messages. If a material document is returned, it means BAPI call was successful irrespective of messages. I find BAPIs implementation of handling return message quite inconsistent. Some BAPIs return a success message, some don't.
Ad Q2, Q3 Always call BAPI_TRANSACTION_COMMIT or BAPI_TRANSACTION_ROLLBACK after a BAPI call depending on result. BAPI_TRANSACTION_COMMIT and BAPI_TRANSACTION_ROLLBACK not only execute commit / rollback work but also call BUFFER_REFRESH_ALL function.
I have sendRequest using RPCManager in smartclient. but I have to structure chaining execution. I read on internet about jQuery deferred and promise function. But I wonder whether smartclient support execution in sequential task.
Thank you.
queueing may be what are you looking for?
For example:
RPCManager.startQueue();
grid.updateData(record1, function(dsResponse, data, dsRequest){/*callback1*/});
grid.updateData(record2, function(dsResponse, data, dsRequest){/*callback2*/});
RPCManager.sendQueue(function(responses){/*finalCallback*/});
will execute the updates sequentially, in a single request, and the callbacks will be executed sequentially:
callback1
callback2
finalCallback
I am trying to add a WFP filter while holding an NDIS RW lock, but FwpmEngineOpen or FwpmTransactionBegin functions fail.
Is there a limitation that prevents these functions to work at Dispatch level?
Thanks!
The documentation for FwpmEngineOpen0 states that the requirement is IRQL == PASSIVE_LEVEL, so it won't work in DISPATCH_LEVEL.
We have some business requirements that call for versioning. We chose to use MarkLogic library services for that. We have an issue testing our code with XRAY and using transactions.
Our test is as follows:
declare function should-save-with-version-when-releasing() {
declare option xdmp:transaction-mode "update";
let $uri := '/some-document-uri.xml'
let $document := fn:doc($uri)
let $pre-release-version := c:get-latest-version($uri)
let $post-release-version := c:get-latest-version($uri)
let $result := mut:release($document) (:this should version up:)
return (assert:not-empty($pre-release-version),
assert:not-empty($result),
assert:not-equal($pre-release-version,$post-release-version),
xdmp:rollback())
The test will pass no matter what, and as it turns out ML rollback demolishes all the variables.
How do we test it using transactions?
Any helps greatly appreciated,
im
With MarkLogic an entire XQuery update normally acts like a single transaction. When mut:release adds an update to the transaction's stack, the rest of the query will not see that update until after it commits. From the point of view of the query, this normally happens after the entire query finishes, and is not visible to the query.
The docs have something useful to add about what http://docs.marklogic.com/xdmp:rollback does:
When a transaction is rolled back, the current statement immediately
terminates, updates made by any statement in the transaction are
discarded, and the transaction terminates.
So it isn't that the variables are demolished: it's that your program is over.
I think http://docs.marklogic.com/guide/app-dev/transactions#id_15746 has an example that is fairly close to your use-case: "Example: Multi-statement Transactions and Same-statement Isolation". It demonstrates how to xdmp:eval or xdmp:invoke to update a document and see the results within the same query.
Test it to see that it works, then replace the xdmp:commit with an xdmp:rollback. For me the example still works. Start replacing the rest of the logic with your unit test logic, and you should be on your way.