I'm using siddhi to create some app which also interacts with PostgreSQL DB. Although I'm not sure, I believe, there is a bug about making multiple updates on the same PG table, within a single event (i.e. upon receiving an event, update a record in the table, and create another one again in the same table) it seems the batch updates are causing some problems. SO, I just want to give it a try after disabling batchUpdate (it is enabled by default). I just don't know how to configure it using siddhi-sdk (via Intellij plugin). There are two related tickets:
https://github.com/wso2-extensions/siddhi-store-rdbms/issues/43
https://github.com/wso2/product-sp/issues/472
Until these are documented, I'd like to get some quick response how to set these fields.
Best regards...
I'm using siddhi to create some app which also interacts with PostgreSQL DB. Although I'm not sure, I believe, there is a bug about making multiple updates on the same PG table, within a single event (i.e. upon receiving an event, update a record in the table, and create another one again in the same table) it seems the batch updates are causing some problems.
When batchEnabled has been set to true, it will perform the insert/update operation on batch of events instead of performing those operations on each and every single event. Simply, this has been introduced to improve the performance.
The default value of this parameter is currently set to "true".
However, batchEnable configurations is done through a system parameter called, "{{RDBMS-Name}}.batchEnable" which have to be configured in the WSO2 Stream Processor's deployment.yaml
If you want to overide this property in Product-SP please find the steps below.
Open the deployment.yaml file located in {Product-SP-Home}/conf/editor/
Insert the following lines in the file.
siddhi:
extensions:
extension:
name: store
namespace: rdbms
properties:
PostgreSQL.batchEnable: true
But currently there is no way to overwrite those system configurations from the siddhi app level. Since you are using the SDK, what you can do is changing the default value of above parameter to "false".
Please find the steps below do it.
Find the siddhi-store-rdbms-4.x.xx.jar file in the siddhi
sdk. This is located in the {siddhi-sdk-home}/lib/ .
Open the jar file using an archive manager and open the
rdbms-table-config.xml file located inside it with a text editor.
Set false in <batchEnable>true</batchEnable> attribute under the
<database name="PostgreSQL"> tag and save it.
Thanks Raveen. with a simple dash (-) before "extension" I was able to set the config.
siddhi:
extensions:
- extension:
name: store
namespace: rdbms
properties:
PostgreSQL.batchEnable: false
Related
I have a service running on my linux machine that reads data stored in a .json file when the machine is booting. The service then validates the incoming JSON data and modifies specific system configurations according to the data. The service is written in C++ and for the validation im using https://github.com/pboettch/json-schema-validator.
In development it was easy to modify the JSON schema and just adapt the data manually. I've started to use semantic versioning for my JSON schema and included it the following way:
JSON schema:
{
"$id": "https://my-company.org/schemas/config/0.1.0/config.schema.json",
"$schema": "http://json-schema.org/draft-07/schema#",
// Start of Schema definition
}
JSON data:
{
"$schema": "https://my-comapny.org/schemas/config/0.1.0/config.schema.json",
// Rest of JSON data
}
With the addition of the version, I am able to check if a version mismatch exists before validating.
What I am looking for is a way to automatically migrate the JSON data to match the newer schema version, if a version mismatch is identified. Is there any way to automatically achieve this, or is the only way to manually edit the JSON data to match the schema?
Since I plan on releasing this as open source I would really like to include some form of automatic migration so I can just ask the user if he wants to migrate to conform to the newest schema version instead of throwing an error, if a version mismatch was identified.
What you're asking for is something which will need to make assumptions to work.
This is an age old problem and similar for databases. You can have schema migrations generated with many simple changes, but this is not viable if you wish to translate existing data automatically too.
Let's look at a basic example. You rename a field.
How would a tool know you've renamed a field vs removed an old one and added a new one? It essentially, cannot.
So, you need to write your migrations by hand.
You could use JSON transformation tools like jq or fx to create migration scripts without writing it in code, which may or may not be preferable. (jq has a steeper learning curve but it's also very powerful.)
I have created a DynamoDb table in my dev machine and I'm trying to insert couple of rows from my .NET Core application using the CreateBatchWrite<T> method of DynamoDBContext object. I'm able to query the table from DynamoDB Javascript Shell window from the localhost:8000/shell url and it returns row count as 0. But when trying to call the CreateBatchWrite<T> method I get the error, "Entity doesn't exist in AsyncLocal".
Explanation
When using X-Ray, this happens when there is an attempt to create a SubSegment without a Parent Segment. Depending on your setup, when you run a query it might try creating a SubSegment, but it's failing because there is no parent segment.
This is common when running a Lambda function locally, as the Mock Lambda Test Tool will not create a Segment for you like the actual Lambda environment does on AWS. This can happen in other scenarios too.
More details here: https://github.com/aws/aws-xray-sdk-dotnet/issues/125
Solution
Easiest way to solve this is disabling X-Ray locally (as you probably don't want to generate traces locally):
In appsettings.Development.json add this:
"XRay": {
"DisableXRayTracing": "true",
"UseRuntimeErrors": "false",
"CollectSqlQueries": "false"
}
The important bit is the DisableXRayTracing equals true.
Make sure your appsettings.Development.json is set to Copy Always in the properties window. You can do this by including this in your .csproj:
<ItemGroup>
<None Update="appsettings.Development.json">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
<None Update="appsettings.json">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>
If you really want to trace things locally, then make sure you create
a parent segment only when running locally (on AWS this would cause
problems as you would have two parent segments, one created manually
by you, another one created by AWS).
Add this line before any DynamoDB API methods are executed:
AWSXRayRecorder.Instance.ContextMissingStrategy = ContextMissingStrategy.LOG_ERROR;
You can find more info in GitHub discussion https://github.com/aws/aws-xray-sdk-dotnet/issues/69#issuecomment-482688754
Also, you will need to import these 2 packages.
using Amazon.XRay.Recorder.Core;
using Amazon.XRay.Recorder.Core.Strategies;
If you are tracing requests made with the AWS SDK, the X-Ray SDK attempts to generate a subsegment automatically to represent those requests, such as CreateBatchWrite. However, a subsegment can only be created as the child of an existing Segment, so if you have not created a segment beforehand that Entity doesn't exist error will occur.
See these docs for how to create custom segments. Alternatively, if you are developing a web app, the X-Ray SDK can automatically create segments for requests made to your service by adding configuration described in these docs
Currently I am using a DynamoDB instance for my social media application. While designing the schema I sticked to the "one table" rule. So I am putting every data in the same table like posts, users, comments etc. Now I want to make flexible queries for my data. Here I found out that I could use the #searchable annotation to create an Elastic Search instance for a table which is annotated with #model
In my GraphQL schema I only have one #model, since I only have one table. My problem now is that I don't want to make everything in the table searchable, since that would be most likely very expensive. There are some data which don't have to be added to the Elastic Search instance (For example comment related data). How could I handle it ? Do I really have to split my schema down into multiple tables to be able to manage the #searchable annotation ? Couldn't I decide If the row should be stored to the Elastic Search with help of the Partitionkey / Primarykey, acting like a filter ?
The current implementation of the amplify-cli uses a predefined python Lambda that are added once we add the #searchable directive to one of our models.
The Lambda code can not be edited and currently, there is no option to define a custom Lambda, you read about it
https://github.com/aws-amplify/amplify-cli/issues/1113
https://github.com/aws-amplify/amplify-cli/issues/1022
If you want a custom Lambda where you can filter what goes to the Elasticsearch Instance, you can follow the steps described here https://github.com/aws-amplify/amplify-cli/issues/1113#issuecomment-476193632
The closest you can get is by creating a template in amplify\backend\api\myapiname\stacks\ where you can manage all the resources related to Elasticsearch. A good start point is to
Add #searchable to one of your model in the schema.grapql
Run amplify api gql-compile
Copy the generated template in the build folder, \amplify\backend\api\myapiname\build\stacks\SearchableStack.json to amplify\backend\api\myapiname\stacks\
Remove the #searchable directive from the model added in step 1
Start editing your new template copied in step 3
Add a Lambda and use it in the template as the resolver for the DynamoDB Stream
Using this approach will give you total control of the resources related to the Elasticsearch service, but, will also require to do it all by your own.
Or, just go by creating a table for each model.
Hope it helps
It is now possible to override the generated streaming function code as well.
thanks to the AWS Support for the information provided
leaved a message on the related github issue as well https://github.com/aws-amplify/amplify-category-api/issues/437#issuecomment-1351556948
All you need is to run
amplify override api
edit the corresponding overrode.ts
change the code with the resources.opensearch.OpenSearchStreamingLambdaFunction.code
resources.opensearch.OpenSearchStreamingLambdaFunction.functionName = 'python_streaming_function';
resources.opensearch.OpenSearchStreamingLambdaFunction.handler = 'index.lambda_handler';
resources.opensearch.OpenSearchStreamingLambdaFunction.code = {
zipFile: `
# python streaming function customized code goes here
`
}
Resources:
[1] https://docs.amplify.aws/cli/graphql/override/#customize-amplify-generated-resources-for-searchable-opensearch-directive
[2]AWS::Lambda::Function Code - Properties - https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-lambda-function-code.html#aws-properties-lambda-function-code-properties
I have a WSO2 Goverance Registry setup conformant to this blog post http://blog.shelan.org/2013/02/application-governance-with-wso2-greg.html.
When defining a new application in the WSO2 GR using the menu: Metadata > Add > Application I would like to be able to directly add the actual application artifact (war/car file).
The selected file should then by placed in the SVN location conforming to the initial state of the lifecycle to which I will bind the application. This of course implies that I would also need to be able to directly add the lifecycle when defining a new application.
The new application form would then be something like this:
Name: ExampleApplication-1.0.0
Type: .war (is now redundant)
Description: My Example Application Artifact: Selected file
ExampleApplication-1.0.0.war Lifecyle: MyDTAP-Lifecycle_v1
Does anybody know a good starting point for adding this functionality in terms of code hooks or extension points?
If I have understood you correctly, what you need to do is basically provide an file upload option in your "Application" RXT (Governance Artifact Configuration) which will upload what ever your file type and based on that you want to fill the derivable information to the meta data of the artifact. And also to attach a selected/pre defined life cycle to it at artifact creation. What you are looking for is Registry Handlers [1]. You can achieve all aforementioned tasks probably through a single handler.
[1] - http://docs.wso2.org/wiki/display/Governance453/Handlers
How can I programmatically dump/query Launch Services database in MacOS (i.e. analog of command lsregister -dump)?
EDIT: I want to get set of associations UTI -> Bundle_IDs. Using LSCopyAllRoleHandlersForContentType - does not always work, here a similar trouble, therefore concluded that the best working method - parsing the output of "lsregister -dump", but the location of lsregister changes from version to version.