Terraform apply parallelism. Feb 23, 2026 · Description: Speed up Terraform apply operations by tuning the -parallelism flag to control concurrent resource operations while avoiding API rate limiting. To enforce parallelism=1 for Terraform operations in stacks created from a blueprint, you need to add specific environment variables to your blueprint configuration. May 9, 2022 · Parallelism is disabled, and it doesn't make sense to break down the state further. Jan 11, 2021 · Stages are executed in parallel (on same node/agent) and each of them consists of the same sequence of operations (terraform workspace select and then terraform apply). With AWS ParallelCluster, you can Sep 4, 2020 · When I use count or for_each in my resource definition, the resources are created in parallel. terraform apply -parallelism=1 Proposal Provide a new input called "apply_parallelism" which allows you to set this variable per workspace. . 65 Found a workaround to use terraform apply --parallelism=1. Today I want to present how to improve terraform plan and terraform apply speed by configuring parallelism. Nov 20, 2021 · terraform apply If you find this is slowing down all Terraform creations but you need this particular set of resources to be deployed one at a time then it might be time to break these particular resources out into their own Terraform config directory and apply it in a different step to the rest of the resources again with the parallelism setting. aws-parallelcluster Provider AWS ParallelCluster is an AWS supported open source cluster management tool that helps you to deploy and manage high performance computing (HPC) clusters in the AWS Cloud. Current mechanism terraform apply -parallelism=1 Purposed mechanism export T Feb 6, 2024 · For example, terraform apply -parallelism=1 tells Terraform to make the changes with no more than 1 terraform apply operation running at the same time. Built-in defaults control the parallelism, but it's also possible to tune some parameters using environment variables specific to the exporter: Mar 5, 2026 · A battle-tested approach to structuring Terraform and Terragrunt for multi-account AWS environments with Atlantis, policy enforcement, and cost controls. Imperva recommends the latter and setting the value to 1. One of these is to control the parallelism of operations that Terraform performs. Se você usa ECS Fargate com múltiplos serviços internos e ainda não conhecia o Cloud Map, vale testar. The default value is 10. Memory + Concurrency The amount of memory to allocate to a Terraform run and the number of concurrent runs are the primary elements in understanding capacity above the base services. Normally this Cause: Prior to migrating from the worker to the agent, Terraform Cloud used this environment variable to control the value passed to the -parallelism argument. Sep 3, 2025 · The parallelism flag isn't really meant to be a solution for API rate limits, it is used for the graph walk, applying equally to every object Terraform evaluates. Is it possible to disable parallelism per provider via terraform configuration? How SREs Handle Parallel Pipeline Executions Written in Terraform Site Reliability Engineers (SREs) play a critical role in ensuring that services are reliable, scalable, and efficient. 6+. Jan 21, 2026 · Terraform Tests Write effective Terraform tests using the native testing framework introduced in Terraform 1. If something isn't dependent on something else then it will execute it in parallel up to the number specified by the -parallelism flag which defaults to 10. Jun 14, 2022 · In my previous post I showed how to enable debug logs. Your other option here would be to force Terraform to create dependencies between these resources in the graph by using the depends_on configuration block. The `terraform plan` command creates an execution plan with a preview of the changes that Terraform will make to your infrastructure. Best Practices Standard workflow is plan, then confirm with user, then apply: Run terraform plan, summarize changes to user, get explicit confirmation, then run terraform apply Summarize changes to user: Before running terraform apply, always show the user a summary of To speed up export, Terraform Exporter performs many operations, such as listing & actual data exporting, in parallel using Goroutines. The -parallelism flag controls how many resource operations happen at the same time. The Fix: Use the -parallelism flag in your CLI or configure the provider’s http settings to limit concurrent connections. Jan 24, 2021 · I am fairly new to terraform and hoping to get some input. 5 Expected Behavior parallelism flag should be replaced with concurrency or something else that declares the process is concurrent. Some teams continue Nov 17, 2024 · As a software development service provider, we understand the importance of optimizing Terraform performance in large-scale environments. May 5, 2017 · As a Terraform User, I should be able to specify a parallelism count on resource instances containing a count parameter So That I Can handle creating API resources via providers at a more sane rate Parallelism refers to the number of tasks the Terraform CLI performs simultaneously in a single workload. By default, Terraform performs a maximum of 10 operations in parallel. Every run had this argument specified at the end of the arguments passed to terraform plan and terraform apply. Increasing parallelism can reduce apply time but may trigger provider throttling or overwhelm your network. Nov 28, 2019 · when I am running terraform apply (with default options), but when I use terraform apply -parallelism 1 then everything works ok. Environment variables are used to increase the output verbosity for debugging or to set rarely used runtime parameters. You can adjust the number of concurrent operations with the -parallelism flag. e. But there was another solution that came to light after poking through the repository code for AzAPI. First I was trying to just use a local-exec provisioner a Apr 23, 2021 · Note that this parallelism is markedly different from the one you specify using Terraform directly. Apr 12, 2022 · As you have noted, Terraform does not currently have a way to ensure these resources are created serially and in order - it will create them in parallel. By default, Terraform Enterprise allocates 512 MB of memory to each Terraform run, with a default concurrency of 10 parallel runs. In this video we are going to cover Optimizing Terraform Apply-Debugging and Parallel Execution Techniques | Terraform Tutorial for Beginners#devopshint #ter Mar 24, 2020 · How to work parallel while applying changes to terraform If you are working on something called IaC, then this is the article for you. For many workloads, you can increase this to significantly reduce apply times. Feb 8, 2017 · Hi Terraform Version 0. Is there any limitation with that provisioner? Nov 22, 2023 · Obviously the simple solution would be to drop apply and destroy parallelisation down to 1, slowly the entire deployment and destroy runs down significantly given everything would then be serialised unnecessarily. When running a terraform apply command, Terraform refreshes each resource in the state file and compares to the remote object. O repositório tem tudo pronto pra subir num terraform apply. In this blog post, we will explore Terraform parallelism: what it is, how to manage it, and best practices for configuring parallelism in Terraform. g. May 5, 2017 · As a Terraform User, I should be able to specify a parallelism count on resource instances containing a count parameter So That I Can handle creating API resources via providers at a more sane rate May 27, 2025 · Describe the bug Since recently updating Terragrunt, we have noticed that it no longer respects the parallelism flag nor passes it to Terraform. Jun 18, 2025 · One example being Terraform resources that create git commits. hcl files and how different blocks work together. To reduce execution time on plan or apply operation we can increase this parameter. 8. For example, parallelism is one of the environment variable with a number flag range between 1 and 256, the default value is 10. , the AWS API). The primary consideration when changing this is rate limiting on the service side (e. Current mechanism terraform apply -parallelism=1 Purposed mechanism export T Jan 7, 2026 · terraform apply -parallelism=<n> lets you specify the number of operations run in parallel. Is there a kind of workaround to make it sequential? First a resource with count. The command attribute and plan_options block tell Terraform which command and options to execute for each run block. The default is 10, which is conservative. Terraform 0. Aug 3, 2021 · You can set the amount of resources and data sources Terraform will process in parallel by using the -parallelism flag which defaults to 10. This article outlines several approaches for managing provider rate limits and improving run performance This is an issue because we might have to update rbac multiple times a day, running terraform apply each time. 5 vsphere provider v1. If you use parallelism=1 everything is single threaded so it could get quite slow. 6 days ago · Terraform CLI Reference Terraform is an infrastructure as code tool for building, changing, and versioning infrastructure. I am still hitting the rate limit, and as such, all terraform refresh and terraform apply operations fail for this state. Jul 3, 2024 · Discover the two main Terraform and OpenTofu workflows: apply-before-merge and apply-after-merge, and learn why apply-after-merge is likely the better choice. Parallel runs can improve the efficiency of infrastructure changes, particularly for large-scale projects. Example Usage Jan 11, 2023 · 3 terraform destroy is an alias for terraform apply -destroy, and terraform apply has a default -parallelism of 10, meaning terraform will process up to 10 resources at a time. This is an issue because we might have to update rbac multiple times a day, running terraform apply each time. Feb 10, 2022 · この記事では、インフラエンジニアの頭を悩ませるそんなお悩みを解決し、 Terraformでの変更を高速化する3つの方法を共有します。 --parallelism オプションで 並列処理の数を増やす Terraform公式で -parallelism というオプションが存在します。 Senior Tip: Mention parallelism & execution plan graph. It looks like somewhere between 50 and 100 is my sweet spot, when experimenting with a batch of 100 instances. Feb 10, 2022 · この記事では、インフラエンジニアの頭を悩ませるそんなお悩みを解決し、 Terraformでの変更を高速化する3つの方法を共有します。 --parallelism オプションで 並列処理の数を増やす Terraform公式で -parallelism というオプションが存在します。 The terraform apply command executes the actions proposed in a Terraform plan to create, update, or destroy infrastructure. 0). tftest. To enable parallelism, several approaches are typically employed: Using Terraform’s Built-in Parallelism: The terraform apply command supports a -parallelism flag to control concurrency at the resource level within a single execution. So by default, terraform is already destroying the resources in parallel. The `terraform apply` command executes the actions proposed in a Terraform plan to create, update, or destroy infrastructure. You can use AWS ParallelCluster with AWS Batch and Slurm schedulers. Feb 23, 2026 · Configure and tune Terraform resource parallelism to speed up infrastructure provisioning while avoiding rate limits and race conditions. This article outlines several approaches for managing provider rate limits and improving run performance Senior Tip: Mention parallelism & execution plan graph. Terraform uses environment variables to customize aspects of its behavior. Jan 26, 2026 · Tip: Use terraform apply -parallelism=20 (or another appropriate number) to speed up deployments, especially when working with independent resources that don’t have dependencies on one another. Prior to migrating from the worker to the agent, Terraform Cloud used this environment variable to control the value passed to the -parallelism argument. For teams that use Terraform as a key part of a change management and deployment pipeline, it can be desirable to orchestrate Terraform runs in some sort of automation in order to ensure consistency between runs, and provide other interesting features such as integration with version control hooks. The default operation, if you do not specify a command attribute or the plan_options block, is a normal Terraform apply operation. In this guide, you learned how to create a basic Terraform setup, use TF_LOG=DEBUG to see detailed logs, speed up execution using the -parallelism flag, and reduce unnecessary outputs to make your plans faster. It doesn't seem supported as the attempts fail with lock errors, e. Steps To Reproduce TF_LOG=TRACE terragrunt apply -pa command — apply (default) or plan variables — Override test-level variable values module — Reference alternate modules (local or registry sources only) assert — Validation conditions (multiple allowed) expect_failures — Specify expected validation failures plan_options — Configure plan behavior (mode, refresh, replace, target) state_key — Manage state file isolation parallel Nov 17, 2024 · As a software development service provider, we understand the importance of optimizing Terraform performance in large-scale environments. Frequently asked Mar 27, 2024 · Optimizing Terraform's performance, especially for plan and apply operations can involve several strategies. Parallelism Parallelism Terraform uses goroutines to speed up deployment, but if the number of parallel operations launched exceeds what is recommended: Terraform has a depends_on clause you could use if all resources are in the same state. Terraform creates, updates, and destroys resources in parallel by default. For the example at the start of this section, the order for the apply-all command would be: Deploy the VPC Deploy MySQL and Redis in parallel Deploy the Nov 29, 2025 · Using this flag can cut down plan and apply times significantly — potentially dropping a 3–5 minute operation down to just 30–60 seconds. 1 day ago · Pra comunicação interna isso raramente importa — o Service Connect já traz métricas e os health checks do ECS cuidam das tasks. May 8, 2025 · Debugging and optimizing Terraform is important, especially for beginners who face slow terraform apply times or unexpected errors. The TFE_PARALLELISM variable sets the -parallelism=<N> flag for terraform plan and terraform apply (more about parallelism). We will explore what constitutes a well-architected cloud environment for CI/CD, the principles of parallelism in pipeline execution, and how Terraform can be leveraged to facilitate this Jul 5, 2019 · 1 Terraform builds a directed, acyclical graphic (also referred to as a DAG) to understand the dependencies between things. How Terraform parallelism works Terraform is an IaC tool. But this are a rare exception in my repo, so I want to set ATLANTIS_PARALLEL_POOL_SIZE<0 and ATLANTIS_PARALLEL_APPLY=true for my server/repo and also be able to overwrite the behaviour when invoking atlantis for this single PR. It is set using the -parallelism flag, with a default value of 10. Feb 12, 2021 · Feature Request Terraform should support environment variables like TF_parallelism to supplement command line arguments. 1 Trying to provision 2 VMs in parallel. ---Th Jun 28, 2019 · However, if I run it again with terraform apply -var="majorVersion=v2" I want terraform to leave the resources of v1 alone! Instead terraform wants to tear down v1!! How can I accomplish a parametrised set of configurations without having to write the whole shebang all over again for each version? It seems tedious and beside the point! Aug 25, 2023 · Discover the ultimate Terraform cheat sheet with essential commands for managing infrastructure, deployment, state management, and more. Example call: terraform apply -parallelism=1. Some cloud providers (like Nov 5, 2025 · Terraform test files use the . You use Terraform to provision resources in remote systems using their APIs through Terraform providers. Use clear naming conventions to distinguish between unit tests (plan mode) and integration tests (apply mode): Discover how to effectively manage `parallel terraform apply` commands in Terraform Cloud, especially for multiple GCP projects in different workspaces. You can either use depends_on or specify the parallelism flag. By increasing parallelism you can hit the rate limit of your provider. Jun 10, 2021 · Thanks a lot @apparentlymart - I didn’t know about refresh=false - it seems to work with destroying too. Recommendation Success with using custom values for TFE_PARALLELISM is highly dependent on each individual case. El paralelismo se utiliza para configurar proveedores de infraestructura que se equivocan en operaciones concurrentes o utilizan durante la limitación de velocidad no estándar, cuando se ejecuta terraform plan y terraform apply en tiempo de State vs Reality: Terraform state may show empty while infrastructure has running resources Interrupted Operations: Destroy/apply operations interrupted before state update completion Jun 10, 2021 · Thanks a lot @apparentlymart - I didn’t know about refresh=false - it seems to work with destroying too. It's a lot slower but so far it's been working for me. Dec 29, 2025 · However, you can take some steps to reduce the time it takes to provision a specific Terraform configuration. Use HCP Terraform agents to manage infrastructure in private networks. The command attribute states whether the operation should be a plan or an apply operation. 612s $ time terraform apply -refresh You are considering changing `parallelism` in your Terraform Enterprise or Terraform Cloud backed workspaces. When to Use This Skill User asks to "write Terraform tests", "create test file", "add test coverage" Implementing test-driven development (TDD) for infrastructure Validating Oct 26, 2018 · 環境変数でも効いてますね。 applyの場合は、環境変数 TF_CLI_ARGS_apply です。 どれぐらいの並列度が最適なのかは場合によりけりなのだけど、めっちゃ簡単なので試してみて損はないですね。 たまたまTerraform のissueを眺めてたら見つけたんだけど、 Nov 20, 2021 · terraform apply If you find this is slowing down all Terraform creations but you need this particular set of resources to be deployed one at a time then it might be time to break these particular resources out into their own Terraform config directory and apply it in a different step to the rest of the resources again with the parallelism setting. Terraform by default runs 10 concurrent operations. Some teams continue Jul 13, 2016 · The problem is that even if Terraform sends 100 requests in parallel (-parallelism 100) they'll only be processed one by one. Once you’ve specified the dependencies in each terraform. Por ejemplo, el paralelismo es una de las variables de entorno con un rango de indicadores numéricos entre 1 and 256, el valor por defecto es 10. Jan 11, 2023 · 3 terraform destroy is an alias for terraform apply -destroy, and terraform apply has a default -parallelism of 10, meaning terraform will process up to 10 resources at a time. $ time terraform apply -refresh=false -var="instance_count=100" -parallelism=10 real 9m24. The -parallelism option is useful when you want to limit the number of concurrent operations inside your cloud provider. Parallelism In workspaces, you can use the TFE_PARALLELISM environment variable when your infrastructure providers produce errors on concurrent operations or use non-standard rate limiting. Learn how to install, configure, and run agents on your own infrastructure. It asks for confirmation from the user before making any changes, unless it was explicitly told to skip approval. 0, you can deploy clusters and custom images using Terraform. Actual Behavior -parallelism=n Limit the Apply The terraform apply command performs a plan just like terraform plan does, but then actually carries out the planned changes to each resource using the relevant infrastructure provider's API. Setting parallelism to 1 avoids hitting the rate limit as it’s currently implemented. Terraform is declarative, meaning that you Feb 12, 2021 · Feature Request Terraform should support environment variables like TF_parallelism to supplement command line arguments. terraform apply -refresh-only : Refresh the state without applying changes (available from Terraform 1. If I could specify through the resource that the rules are only to be done with parallelism 1, then Terraform would be able to do other operations in parallel instead and optimise the deployment time. Adjust -parallelism based on provider limits and infrastructure complexity. 24. 14. 2️⃣ What happens if two engineers run terraform apply at the same time? 👉 If remote backend with locking (S3 + DynamoDB) is enabled The `terraform plan` command creates an execution plan with a preview of the changes that Terraform will make to your infrastructure. Change this to -parallelism=5 will increase the number to 5, and so on. Jul 12, 2025 · Strategy 3: Parallelism and API Rate Limiting If you try to create 50 VMs at once, the Proxmox API (which is just a web service on the host) might become overwhelmed and start returning 500 errors. It is also not possible to use count to create dependencies between resource instances, because Terraform's dependency graph operates on resources, not resource instances. May 12, 2025 · This article delves into the intricacies of cloud re-architecture, focusing on parallel pipeline executions and their implementation using Terraform. index=0 is created, t The terraform apply command executes the actions proposed in a Terraform plan to create, update, or destroy infrastructure. 612s $ time terraform apply -refresh For teams that use Terraform as a key part of a change management and deployment pipeline, it can be desirable to orchestrate Terraform runs in some sort of automation in order to ensure consistency between runs, and provide other interesting features such as integration with version control hooks. Most use case of this approach is, If you think the … Terraform uses environment variables to customize aspects of its behavior. Jul 3, 2019 · Getting same problems with azurerm 2. Re-apply with a narrower scope Re-run Terraform with targeted resources to reduce waiting on non-critical updates. Feb 23, 2026 · Terraform creates, updates, and destroys resources in parallel by default. However, this is limited to a single plan and does not inherently support multiple pipelines. The parallel_runs configuration in Terrateam specifies how many concurrent Terraform runs can be executed across different directories or environments. Use the navigation to the left to read about the available resources. tfvars file, when you run the terragrunt apply-all or terragrunt destroy-all, Terragrunt will ensure that the dependencies are applied or destroyed, respectively, in the correct order. This skill covers the syntax and structure of . This article Jun 19, 2021 · Use-cases There are sometimes bugs which need serial execution i. Introduction You may need to adjust the TFE_PARALLELISM environment variable in Terraform Enterprise or HCP Terraform when infrastructure providers produce errors during concurrent operations or enforce non-standard rate limiting. index=0 is created, t The current API that the Incapsula provider is calling requires sequential execution. 2️⃣ What happens if two engineers run terraform apply at the same time? 👉 If remote backend with locking (S3 + DynamoDB) is enabled Beginning with AWS ParallelCluster 3. You could set this to 1 and then Terraform will only process one resource at a time. Handle timeouts safely If Terraform times out during long-running operations, confirm completion in the console, adjust provider timeouts if supported, and re-apply only after the previous operation has finished. You can of course change this argument to a lower or higher value as needed. Oct 26, 2018 · 環境変数でも効いてますね。 applyの場合は、環境変数 TF_CLI_ARGS_apply です。 どれぐらいの並列度が最適なのかは場合によりけりなのだけど、めっちゃ簡単なので試してみて損はないですね。 たまたまTerraform のissueを眺めてたら見つけたんだけど、 Jul 13, 2016 · The problem is that even if Terraform sends 100 requests in parallel (-parallelism 100) they'll only be processed one by one. It looks like this can be reduced somewhat with increasing the parallelism arg, but want to know what I need to configure in either terraform or the host machine (running terraform) to make sure it is actually working optimally. Dec 29, 2025 · Terraform parallelism controls the number of concurrent resource operations during a terraform apply or terraform destroy. Automation of Terraform can come in various forms, and to varying degrees. One of the fundamental aspects of modern DevOps practices is the utilization of Infrastructure as Code (IaC) tools, like Terraform, to manage cloud resources efficiently and in an automated manner. The parallelism is making things better as well. To begin using this feature, see Terraform Provider for AWS ParallelCluster from the Terraform Registry. Optimise Provider Configuration Sometimes, Terraform performs checks that aren’t strictly necessary for every single run, especially in non-production environments. json extension and are typically organized in a tests/ directory. terraform apply -parallelism=30 4. It automatically sets up the required compute resources, scheduler, and shared filesystem. Aug 21, 2023 · We have developed a terraform provider for an internal API that has recently implemented some aggressive rate limiting functionality. With Terraform, parallelism indicates running resource creation concurrently. Here are some tips to help speed up these commands: Parallelism Adjustment: Terraform performs operations concurrently. Mar 13, 2026 · This Terraform Cheat Sheet guide (+pdf) will help you get straight to the commands you need when using the Terraform CLI! Dec 11, 2024 · terraform apply -parallelism=4 : Limit the number of concurrent resource operations during apply. Sep 4, 2020 · When I use count or for_each in my resource definition, the resources are created in parallel. hcl or . Terraform is a powerful tool for managing infrastructure as code, but as your infrastructure grows, you may encounter performance issues that can slow down deployment times and impact overall efficiency. pcwfjs aoeqnq fczfua chxiehfb cxrrwp pzww jll gfijfov mcmpjmz zotqqwb