I have 3 mapper and their labelled as initializeRun, targetSchema, currentRecord. initializeRun is the second snap in the pipeline and others are somewhere in middle and last. I have to use the output of initializeRun into an router snap which is after the currentRecord mapper snap. What will be better approach?
Great question! This is a common pipeline design challenge in SnapLogic. Here's a thorough breakdown of the best approaches to carry the output of initializeRun (Mapper 2) forward to a Router Snap that comes after currentRecord (the last Mapper). --- π§© The Challenge Your pipeline flow looks roughly like this:
[Snap 1] β [initializeRun Mapper] β [...] β [targetSchema Mapper] β [...] β [currentRecord Mapper] β [Router Snap]
You need data from initializeRun to be available at the Router Snap, even though many Snaps sit in between. --- β Recommended Approaches π₯ Option 1: Use a Copy Snap after initializeRun (Best Approach) Place a Copy Snap immediately after the initializeRun Mapper. This forks the data stream into two branches: - Branch 1: Continues the normal flow β targetSchema β currentRecord β Router - Branch 2: Holds/feeds the initializeRun output directly into the Router Snap as a second input Then at the Router Snap, use a Join Snap (with Merge type) just before it to combine the two streams β the enriched stream from currentRecord and the initialization data from initializeRun.
[initializeRun] β [Copy]βββββββββββββββββββββββββββββββββββββββββββ
ββββ [targetSchema] β [currentRecord] β [Join] β [Router]
β οΈ Note: The Join Snap with Merge type works well here if both streams have a 1:1 document relationship. If cardinalities differ, use Left Outer Join with a matching key.
--- π₯ Option 2: Use Pipeline Parameters to Store initializeRun Values If the output of initializeRun contains metadata/configuration values (e.g., run IDs, flags, schema names) rather than large data sets, you can: 1. Use a Mapper after initializeRun to write values into Pipeline Parameters (via expressions like _myParam). 2. Reference those pipeline parameters downstream in the Router Snap's conditions using _paramName.
β οΈ Limitation: Pipeline parameters are best for small metadata, not large datasets. SnapLogic recommends not passing large data through parameters.
--- π₯ Option 3: Pass Data Through Using $original or Field Carry-Forward If the intermediate Mappers (targetSchema, currentRecord) are configured with pass-through fields, you can carry the initializeRun output fields along the entire chain by mapping them through each Mapper snap until they reach the Router. - In each Mapper, add a mapping rule to pass through the initializeRun fields (e.g., $initField β $initField). - By the time the data reaches the Router, all initializeRun fields are still present in the document. --- π Summary Recommendation | Approach | Best When | Complexity | |---|---|---| | Copy + Join | Data volume is significant; clean stream merging needed | Medium | | Pipeline Parameters | initializeRun outputs are small config/metadata values | Low | | Field Carry-Forward | Intermediate Mappers are simple and fields don't conflict | LowβMedium |
π‘ Most robust choice: Use a Copy Snap after initializeRun and a Join (Merge) just before the Router. This keeps your data streams clean and avoids polluting intermediate Mappers with extra pass-through logic.
Would you like me to build this pipeline for you, or help configure any of these Snaps?
It looks like you're sharing a Slack message that mentions using a Group By N Snap with a specific configuration. Let me look that up for you! Here's a summary of how to use the Group By N Snap with a custom Target Field: --- Using the Group By N Snap with a Custom Target Field The Group By N Snap groups multiple input documents into a single output document, where the grouped data is stored as an array at the location specified by the Target field property. Steps to Configure 1. Add the Group By N Snap to your pipeline. 2. Open the Snap settings. 3. Set the Target field to logging (or any desired JSON path). 4. Set the Group size to define how many input documents should be batched together per output document. --- What the Output Looks Like With Target field set to logging, each output document will look like:
json
{
"logging": [
{ ...input document 1... },
{ ...input document 2... },
...
]
}
The grouped input documents will be nested as an array under the logging key. --- Key Properties to Note | Property | Description | Default | |---|---|---| | Target field | JSON path where the grouped array is stored | group | | Group size | Number of input documents per output document | 10 | | Memory Sensitivity | Controls dynamic vs. fixed group sizing | None | | Flush Timeout | Seconds before outputting a partial group | 0 | --- π‘ Tips - You can use a nested JSON path for the Target field, e.g., $logging.records, which would nest the array under logging > records. - If you want to group all input documents into a single output, set Group size to 0. - It's good practice to use a Sort Snap upstream if your data needs to be ordered before grouping. Let me know if you'd like help building or configuring this pipeline! π
