# Configuration ```json metadata { "schema_version": 2, "title": "Configuration", "description": "Configure the operation parameters", "categories": ["docs","develop","stack","oss","rs","rc","oss","kubernetes","clients"], "tableOfContents": {"sections":[{"id":"bootstrap-configuration","title":"Bootstrap configuration"},{"id":"runtime-configuration","title":"Runtime configuration"},{"children":[{"id":"execution-threads","title":"execution-threads"},{"id":"library-fatal-failure-policy","title":"library-fatal-failure-policy"},{"id":"v8-maxmemory","title":"v8-maxmemory"},{"id":"v8-library-initial-memory-usage","title":"v8-library-initial-memory-usage"},{"id":"v8-library-initial-memory-limit","title":"v8-library-initial-memory-limit"},{"id":"v8-library-memory-usage-delta","title":"v8-library-memory-usage-delta"},{"id":"lock-redis-timeout","title":"lock-redis-timeout"},{"id":"db-loading-lock-redis-timeout","title":"db-loading-lock-redis-timeout"},{"id":"remote-task-default-timeout","title":"remote-task-default-timeout"},{"id":"error-verbosity","title":"error-verbosity"}],"id":"configurations","title":"Configurations"}]} , "codeExamples": [] } ``` Redis Stack's triggers and functions feature provides configuration options to control its operation. These options can be set when the module is bootstrapped and, in some cases, at runtime. The following sections describe the configuration options and how to set them. ## Bootstrap configuration You can set your configuration options when the module is loaded. When the module is loaded at start time, the module configuration can be defined in the Redis configuration file. When loading the module at runtime the configuration can be given to the [`MODULE LOADEX`](https://redis.io/docs/latest/commands/module-loadex) command. Each configuration must be prefixed with the module name, `redisgears_2.`. ## Runtime configuration You may set certain configuration options at runtime. Setting a configuration at runtime is done using [`CONFIG SET`](https://redis.io/docs/latest/commands/config-set) command. Here each configuration must be prefixed with the module name, `redisgears_2.`. Example: ```bash > config set redisgears_2.lock-redis-timeout 1000 OK ``` ## Configurations ### execution-threads The `execution-threads` configuration option controls the number of background threads that run JS code. **Note that libraries are considered single threaded**. This configuration allows Redis to parallelize the invocation of multiple libraries. _Expected Value_ Integer _Default_ 1 _Minimum Value_ 1 _Maximum Value_ 32 _Runtime Configurability_ No ### library-fatal-failure-policy The `library-fatal-failure-policy` configuration option controls how to handle a fatal error. A fatal error is consider one of the following: * Block timeout - The function blocks the Redis processes for too long (configurable using the [lock-redis-timeout](#lock-redis-timeout) configuration value) * OOM - The function consumes too much memory (configurable using the [v8-maxmemory](#v8-maxmemory) configuration value). This configuration basically allows choosing between two options: * Do not break atomicity property, even at the cost of killing the Redis processes. * Keep my Redis processes alive, even at the cost of losing atomicity. _Expected Value_ * kill - Save the atomicity property. Risk of killing the Redis processes. * abort - Abort the invocation of the function and keep the Redis processes alive. Risk of losing the atomicity property. _Default_ abort _Runtime Configurability_ Yes ### v8-maxmemory The `v8-maxmemory` configuration option controls the maximum amount of memory used by all V8 libraries. Exceeding this limit is considered a fatal error and will be handled base on the [library-fatal-failure-policy](#library-fatal-failure-policy) configuration value. _Expected Value_ Integer _Default_ 200M _Minimum Value_ 50M _Maximum Value_ 1G _Runtime Configurability_ No ### v8-library-initial-memory-usage The `v8-library-initial-memory-usage` configuration option controls the initial memory given to a single V8 library. This value can not be greater then [`v8-library-initial-memory-limit`](#v8-library-initial-memory-limit) or [v8-maxmemory](#v8-maxmemory). _Expected Value_ Integer _Default_ 2M _Minimum Value_ 1M _Maximum Value_ 10M _Runtime Configurability_ No ### v8-library-initial-memory-limit The `v8-library-initial-memory-limit` configuration option controls the initial memory limit on a single V8 library. This value can not be greater then [v8-maxmemory](#v8-maxmemory). _Expected Value_ Integer _Default_ 3M _Minimum Value_ 2M _Maximum Value_ 20M _Runtime Configurability_ No ### v8-library-memory-usage-delta The `v8-library-memory-usage-delta` configuration option controls the delta by which we will increase the V8 library memory limit once the limit reached. This value can not be greater then [v8-maxmemory](#v8-maxmemory). _Expected Value_ Integer _Default_ 1M _Minimum Value_ 1M _Maximum Value_ 10M _Runtime Configurability_ No ### lock-redis-timeout The `lock-redis-timeout` configuration option controls the maximum amount of time (in MS) a library can lock Redis. Exceeding this limit is considered a fatal error and will be handled based on the [library-fatal-failure-policy](#library-fatal-failure-policy) configuration value. This configuration only affects library loading at runtime with `TFUNCTION LOAD`. The timeout for loading a library from RDB is set separately via [db-loading-lock-redis-timeout](#db-loading-lock-redis-timeout). _Expected Value_ Integer _Default_ 500 MS _Minimum Value_ 100 MS _Maximum Value_ Unlimited _Runtime Configurability_ Yes #### Side effects When setting `lock-redis-timeout`, if the new value is higher than the `db-loading-lock-redis-timeout`, the `db-loading-lock-redis-timeout` is also updated to this value. ### db-loading-lock-redis-timeout This timeout configuration is used for setting the upper time limit (in milliseconds) for the library loading from RDB. _Expected Value_ Integer _Default_ 30000 MS _Minimum Value_ 100 MS _Maximum Value_ Unlimited _Runtime Configurability_ Yes #### Notes The value cannot be lower than the value of `lock-redis-timeout`. ### remote-task-default-timeout The `remote-task-default-timeout` configuration option controls the timeout when waiting for a remote task to finish. If the timeout is reached an error will result. _Expected Value_ Integer _Default_ 500 MS _Minimum Value_ 1 MS _Maximum Value_ Unlimited _Runtime Configurability_ Yes ### error-verbosity The `error-verbosity` configuration option controls the verbosity of error messages that will be provided by triggers and functions. The higher the value the more verbose the error messages will be (for example, including stack traces and extra information for better analysis and debugging). _Expected Value_ Integer _Default_ 1 _Minimum Value_ 1 _Maximum Value_ 2 _Runtime Configurability_ Yes