Each item in my table represents a social media post.
It has the following definition:
{
"title": string,
"user_id": string,
"description: string,
"likes": set,
"comments": list
}
When I'm updating an item, I want to overwrite the existing value if it's a string and add to the existing value if it's a set/list. How do I determine the type of an attribute? Is this the best way to design my table?
Related
I have the following dictionary
plaintext_item = {
"website": "https://example.com",
"description": "This is a sample data",
"website_username": {
"testuser1": "password12",
"testuser2": "password13",
}
}
In the above dictionary I want to encrypt both the passwords but not their usernames and store it in dynamoDb.
what I tried?
This was my first approach but didn't work
actions = AttributeActions(
default_action=CryptoAction.ENCRYPT_AND_SIGN,
attribute_actions={
"website": CryptoAction.DO_NOTHING,
plaintext_item["website_username"]["testuser1"]: CryptoAction.ENCRYPT_AND_SIGN,
"description": CryptoAction.DO_NOTHING,
}
)
Then I tried this below 2nd approach like how we update nested value in dynamodb, this too didn't work
actions = AttributeActions(
default_action=CryptoAction.ENCRYPT_AND_SIGN,
attribute_actions={
"website": CryptoAction.DO_NOTHING,
"website_username.testuser1": CryptoAction.ENCRYPT_AND_SIGN,
"description": CryptoAction.DO_NOTHING,
})
In both the above cases the whole object is getting encrypted and stored, I looked for some documentation but I am not able to find anything related, I am able to encrypt normal dictionaries like {"a":2,"b":3} but not nested ones.
I am working on a POC using Kendra and Salesforce. The connector allows me to connect to my Salesforce Org and index knowledge articles. I have been able to set this up and it is currently working as expected.
There are a few custom fields and data points I want to bring over to help enrich the data even more. One of these is an additional answer / body that will contain key information for the searching.
This field in my data source is rich text containing HTML and is often larger than 2048 characters, a limit that seems to be imposed in a String data field within Kendra.
I came across two hooks that are built in for Pre and Post data enrichment. My thought here is that I can use the pre hook to strip HTML tags and truncate the field before it gets stored in the index.
Hook Reference: https://docs.aws.amazon.com/kendra/latest/dg/API_CustomDocumentEnrichmentConfiguration.html
Current Setup:
I have added a new field to the index called sf_answer_preview. I then mapped this field in the data source to the rich text field in the Salesforce org.
If I run this as is, it will index about 200 of the 1,000 articles and give an error that the remaining articles exceed the 2048 character limit in that field, hence why I am trying to set up the enrichment.
I set up the above enrichment on my data source. I specified a lambda to use in the pre-extraction, as well as no additional filtering, so run this on every article. I am not 100% certain what the S3 bucket is for since I am using a data source, but it appears to be needed so I have added that as well.
For my lambda, I create the following:
exports.handler = async (event) => {
// Debug
console.log(JSON.stringify(event))
// Vars
const s3Bucket = event.s3Bucket;
const s3ObjectKey = event.s3ObjectKey;
const meta = event.metadata;
// Answer
const answer = meta.attributes.find(o => o.name === 'sf_answer_preview');
// Remove HTML Tags
const removeTags = (str) => {
if ((str===null) || (str===''))
return false;
else
str = str.toString();
return str.replace( /(<([^>]+)>)/ig, '');
}
// Truncate
const truncate = (input) => input.length > 2000 ? `${input.substring(0, 2000)}...` : input;
let result = truncate(removeTags(answer.value.stringValue));
// Response
const response = {
"version" : "v0",
"s3ObjectKey": s3ObjectKey,
"metadataUpdates": [
{"name":"sf_answer_preview", "value":{"stringValue":result}}
]
}
// Debug
console.log(response)
// Response
return response
};
Based on the contract for the lambda described here, it appears pretty straight forward. I access the event, find the field in the data called sf_answer_preview (the rich text field from Salesforce) and I strip and truncate the value to 2,000 characters.
For the response, I am telling it to update that field to the new formatted answer so that it complies with the field limits.
When I log the data in the lambda, the pre-extraction event details are as follows:
{
"s3Bucket": "kendrasfdev",
"s3ObjectKey": "pre-extraction/********/22736e62-c65e-4334-af60-8c925ef62034/https://*********.my.salesforce.com/ka1d0000000wkgVAAQ",
"metadata": {
"attributes": [
{
"name": "_document_title",
"value": {
"stringValue": "What majors are under the Exploratory track of Health and Life Sciences?"
}
},
{
"name": "sf_answer_preview",
"value": {
"stringValue": "A complete list of majors affiliated with the Exploratory Health and Life Sciences track is available online. This track allows you to explore a variety of majors related to the health and life science professions. For more information, please visit the Exploratory program description. "
}
},
{
"name": "_data_source_sync_job_execution_id",
"value": {
"stringValue": "0fbfb959-7206-4151-a2b7-fce761a46241"
}
},
]
}
}
The Problem:
When this runs, I am still getting the same field limit error that the content exceeds the character limit. When I run the lambda on the raw data, it strips and truncates it as expected. I am thinking that the response in the lambda for some reason isn't setting the field value to the new content correctly and still trying to use the data directly from Salesforce, thus throwing the error.
Has anyone set up lambdas for Kendra before that might know what I am doing wrong? This seems pretty common to be able to do things like strip PII information before it gets indexed, so I must be slightly off on my setup somewhere.
Any thoughts?
since you are still passing the rich text as a metadata filed of a document, the character limit still applies so the document would fail at validation step of the API call and would not reach the enrichment step. A work around is to somehow append those rich text fields to the body of the document so that your lambda can access it there. But if those fields are auto generated for your documents from your data sources, that might not be easy.
I am using DynamoDB streams to sync data to Elasticsearch using Lambda
The format of the data (from https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Streams.Lambda.Tutorial.html) looks like:
"NewImage": {
"Timestamp": {
"S": "2016-11-18:12:09:36"
},
"Message": {
"S": "This is a bark from the Woofer social network"
},
"Username": {
"S": "John Doe"
}
},
So two questions.
What is the "S" that the stream attaches. I am assuming it is to indicate string or stream, but I can't find any documentation.
Is there an option to exclude this from the stream or do I have to write code in my lambda function to remove it?
What you are seeing is the DynamoDB Data Type Descriptors. This is how data is stored in DynamoDB (or at least how it is exposed via the low level APIs). There are SDKs is various languages that will convert this to JSON.
For Python: https://boto3.amazonaws.com/v1/documentation/api/latest/_modules/boto3/dynamodb/types.html
'TypeSerializer'
deserializer = boto3.dynamodb.types.TypeDeserializer()
dic = {key: deserializer.deserialize(val) for key,val in record['dynamodb']['NewImage'].items()}
def decimal_default(obj):
if isinstance(obj, decimal.Decimal):
return float(obj)
raise TypeError
json.dumps(dic, default=decimal_default)
If you want to index in elasticsearch you have to do another json.loads() to convert to a Python dictionary.
The S indicates that the value of the attribute is simply a scalar string (S) attribute type. Each DynamoDB item attribute's key name is always a string though the attribute value doesn't have to be a scalar string. 'Naming Rules and Data Types' details each attribute data type. A string is a scalar type which is different than a document type or a set type.
There are different views of a stream record however there is no stream view that omits the item's attribute value code and also provides the attribute value. Each possible StreamViewType is explained in 'Capturing Table Activity with DynamoDB streams'.
Have fun!
I'm trying to set up AWS' Cloudsearch with a DynamoDB table. My data structure is something like this:
{
"name": "John Smith",
"phone": "0123 456 789"
"business": {
"name": "Johnny's Cool Co",
"id": "12345",
"type": "contractor",
"suburb": "Sydney"
},
"profession": {
"name": "Plumber",
"id": "20"
},
"email": "johnsmith#gmail.com",
"id": "354684354-4b32-53e3-8949846-211384",
}
Importing this data from DynamoDB -> Cloudsearch is a breeze, however I want to be able to index on some of these nested object parameters (like business.name, profession.name etc).
Cloudsearch is pulling in some of the nested objects like suburb, but it seems like it's impossible for it to differentiate between the name in the root of the object and the name within the business and profession objects.
Questions:
How do I make these nested parameters searchable? Can I index on business.name or something?
If #1 is not possible, can I somehow send my data through a transforming function before it gets to Cloudsearch? This way I could flatten all of my objects and give the fields unique names like businessName and professionName
EDIT:
My solution at the moment is to have a separate DynamoDB table which replicates our users table, but stores it in a CloudSearch-friendly format. However, I don't like this solution at all so any other ideas are totally welcome!
You can use dynamodb streams and write a function that runs in lambda to capture changes and add documents to cloudsearch, flatenning them at that point, instead of keeping an additional dynamodb table.
For example, within my lambda function I have logic that keeps the list of nested fields (within a "body" parent in this case) and I create a just flatten them with their field name, in the case of duplicate sub-field names you can append the parent name to create a new field such as "body-name" as the key.
... misc. setup ...
headers = { "Content-Type": "application/json" }
indexed_fields = ['app', 'name', 'activity'] #fields to flatten
def handler(event, context): #lambda handler called at each update
document = {} #document to be uploaded to cloudsearch
document['id'] = ... #your uid, from the dynamo update record likely
document['type'] = 'add'
all_fields = {}
#flatten/pull out info you want indexed
for record in event['Records']:
body = record['dynamodb']['NewImage']['body']['M']
for key in indexed_fields:
all_fields[key] = body[key]['S']
document['fields'] = all_fields
#post update to cloudsearch endpoint
r = requests.post(url, auth=awsauth, json=document, headers=headers)
So here is my schema:
type Model {
PartitionKey: ID!
Name: String
Version: Int
FBX: String
# ms since epoch
CreatedAt: AWSTimestamp
Description: String
Tags: [String]
}
type Query {
getAllModels(count: Int, nextToken: String): PaginatedModels!
}
type PaginatedModels {
models: [Model!]!
nextToken: String
}
I would like to call 'getAllModels' and have all of it's data, and all of it's tags be filled in.
But here is the thing. Tags are stored via sort keys. Like so
PartionKey | SortKey
Model-0 | Model-0
Model-0 | Tag-Tree
Model-0 | Tag-Building
Is it possible to transform the 'Tag' sort keys into the Tags: [String] array in the schema via a DynamoDB resolver? Or must I do something extra fancy through a lambda? Or is there a smarter way to do this?
To clarify, are you storing objects like this in DynamoDB:
{ PartitionKey (HASH), Tag (SortKey), Name, Version, FBX, CreatedAt, Description }
and using a DynamoDB Query operation to fetch all rows for a given HashKey.
Query #PartitionKey = :PartitionKey
and getting back a list of objects some of which have a different "Tag" value and one of which is "Model-0" (aka the same value as the partition key) and I assume that record contains all other values for the record. E.G.
[
{ PartitionKey, Tag: 'ValueOfPartitionKey', Name, Version, FBX, CreatedAt, ... },
{ PartitionKey, Tag: 'Tag-Tree' },
{ PartitionKey: Tag: 'Tag-Building' }
]
You can definitely write resolver logic without too much hassle that reduces the list of model objects into a single object with a list of "Tags". Let's start with a single item and see how to implement a getModel(id: ID!): Model query:
First define the response mapping template that will get all rows for a partition key:
{
"version" : "2017-02-28",
"operation" : "Query",
"query" : {
"expression": "#PartitionKey = :id",
"expressionValues" : {
":id" : {
"S" : "${ctx.args.id}"
}
},
"expressionNames": {
"#PartitionKey": "PartitionKey" # whatever the table hash key is
}
},
# The limit will have to be sufficiently large to get all rows for a key
"limit": $util.defaultIfNull(${ctx.args.limit}, 100)
}
Then to return a single model object that reduces "Tag" to "Tags" you can use this response mapping template:
#set($tags = [])
#set($result = {})
#foreach( $item in $ctx.result.items )
#if($item.PartitionKey == $item.Tag)
#set($result = $item)
#else
$util.qr($tags.add($item.Tag))
#end
#end
$util.qr($result.put("Tags", $tags))
$util.toJson($result)
This will return a response like this:
{
"PartitionKey": "...",
"Name": "...",
"Tags": ["Tag-Tree", "Tag-Building"],
}
Fundamentally I see no problem with this but its effectiveness depends upon your query patterns. Extending this to the getAll use is doable but will require a few changes and most likely a really inefficient Scan operation due to the fact that the table will be sparse of actual information since many records are effectively just tags. You can alleviate this with GSIs pretty easily but more GSIs means more $.
As an alternative approach, you can store your Tags in a different "Tags" table. This way you only store model information in the Model table and tag information in the Tag table and leverage GraphQL to perform the join for you. In this approach have Query.getAllModels perform a "Scan" (or Query) on the Model table and then have a Model.Tags resolver that performs a Query against the Tag table (HK: ModelPartitionKey, SK: Tag). You could then get all tags for a model and later create a GSI to get all models for a tag. You do need to consider that now the nested Model.Tag query will get called once per model but Query operations are fast and I've seen this work well in practice.
Hope this helps :)