Assignment for model with id already exists – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 8.4-8.7

Briefly, this error occurs when Elasticsearch tries to assign a task to a model that already has an ongoing task. This is common in machine learning jobs where a model is already processing a task and another task is assigned to it. To resolve this issue, you can either wait for the current task to finish before assigning a new one, or you can stop the current task and then assign the new task. Alternatively, you can create a new model and assign the task to it.

This guide will help you check for common problems that cause the log ” assignment for model with id [{}] already exists ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “assignment for model with id [{}] already exists” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 this.modelToAdd = Objects.requireNonNull(modelToAdd);
 }  TrainedModelAssignmentMetadata.Builder rebalance() throws Exception {
 if (modelToAdd.isPresent() && currentMetadata.hasModel(modelToAdd.get().getModelId())) {
 throw new ResourceAlreadyExistsException("assignment for model with id [{}] already exists"; modelToAdd.get().getModelId());
 }  if (modelToAdd.isEmpty() && areAllModelsSatisfiedAndNoOutdatedRoutingEntries()) {
 logger.trace(() -> "No need to rebalance as all model deployments are satisfied");
 return TrainedModelAssignmentMetadata.Builder.fromMetadata(currentMetadata);