# Bursting configuration These Liberator configuration items define the settings of Liberator’s [bursting](liberator-bursting.md) feature. The efficiency of the Liberator can be increased by writing user output in defined "bursts", or "batches". **📌 NOTE**\ For an explanation of how these configuration items control the amount of bursting, see [How bursting works](#how-bursting-works) below. **💡 TIP**\ You can also use Liberator’s [throttling](liberator-throttling.md) feature to reduce the performance impact of high update rates by merging updates together. ## burst-increment `burst-increment` specifies defines the amount by which the batching interval is increased when more than three messages are received and batched within the batching interval (up to a maximum of [burst-max](#burst-max)) , and by which the batching interval is decreased when no messages are received within the batching interval (down to a minimum of [burst-min](#burst-min)). For an explanation of how `burst-increment` works together with [burst-min](#burst-min) and [burst-max](#burst-max), see [How bursting works](#how-bursting-works) below. **Syntax:** `burst-increment ` **Type:** float **Default value:** `0.05` seconds ## burst-max `burst-max` specifies the maximum time in seconds during which messages are batched together before being sent to the client (the batching interval). For an explanation of how `burst-max` works together with [burst-min](#burst-min) and [burst-increment](#burst-increment), see [How bursting works](#how-bursting-works) below. Benchmark testing has shown that the default `burst-max` setting of `0.5` together with the default [burst-min](#burst-min) setting of `0.1` seconds provide the best compromise between performance and display. We recommend that Liberator always has a `burst-max` setting, even if it is small, such as `0.1` seconds. **❗ IMPORTANT**\ A burst-max setting of greater than `0.5` seconds can give a visual effect on the client side that data is being "pulsed" instead of streamed. In the [Caplin Platform Deployment Framework](../deployment-framework/index.md), you use a configuration macro `LIBERATOR${THIS_LEG}_BURST_MAX` to specify Liberator’s `burst-max` value. See Deployment Framework [Configuration macros and items](../deployment-framework/cdf-configuration-macros-and-items.md). Set the macro in the file `/global_config/environment.conf` **❗ IMPORTANT**\ Don’t batch trade messages. The [no-batching](liberator-object-configuration-part-1.md#no-batching) option of [add-object](liberator-object-configuration-part-1.md#add-object) turns off batching of messages for that object, thus overriding the `burst-min`, `burst-increment` and `burst-max` settings. Set `no-batching` to `TRUE` for objects that define the subjects of trade messages, since trade messages should be propagated to clients with minimum possible latency and so must never be batched. **Syntax:** `burst-max ` **Type:** float **Default value:** `0.5` seconds ## burst-min `burst-min` specifies defines the minimum time in seconds during which messages are batched together before being sent to the client (the batching interval). For an explanation of how `burst-min` works together with [burst-max](#burst-max) and [burst-increment](#burst-increment), see [How bursting works](#how-bursting-works) below. **📌 NOTE**\ In the [Caplin Platform Deployment Framework](../deployment-framework/index.md), you use a configuration macro `LIBERATOR${THIS_LEG}_BURST_MIN` to specify Liberator’s `burst-min` value. See Deployment Framework [Configuration macros and items](../deployment-framework/cdf-configuration-macros-and-items.md). Set the macro in the file `/global_config/environment.conf` **❗ IMPORTANT**\ Don’t batch trade messages. The [no-batching](liberator-object-configuration-part-1.md#no-batching) option of [add-object](liberator-object-configuration-part-1.md#add-object) turns off batching of messages for that object, thus overriding the `burst-min`, `burst-increment` and `burst-max` settings. Set `no-batching` to `TRUE` for objects that define the subjects of trade messages, since trade messages should be propagated to clients with minimum possible latency and so must never be batched. **Syntax:** `burst-min ` **Type:** float **Default value:** `0.1` seconds ## How bursting works First, read the [simple explanation of how bursting works](liberator-bursting.md); this simple explanation assumes that only the [burst-max](#burst-max) configuration item controls the bursting behaviour. However, in reality, the [burst-min](#burst-min) and [burst-max](#burst-max) configuration items define a "bursting" time window. The time within this window at which successive messages are batched together can vary according to the value of the [burst-increment](#burst-increment) configuration item and the incoming message rate. This is best shown by an example: Assume: * `burst-min` = `0.1` seconds * `burst-max` = `0.5` seconds * `burst-increment` = `0.05` seconds Call the time interval in which successive messages are batched together `batching_interval`. At the end of each `batching_interval`, the batched messages (if there are any) are sent to the client. Initially `batching_interval` is set to `burst-min`, that is, `0.1` seconds. If Liberator receives one, two or three messages from the supplying DataSource application within that `0.1` seconds, it batches them and sends the batch to the client after `0.1` seconds, and then waits another `0.1` seconds for more incoming messages. However, if Liberator receives more than _three_ messages within a `0.1` seconds `batching_interval`, once it’s sent the batch on to the client, it adjusts `batching_interval` by adding on the `burst-increment`, so the `batching_interval` becomes `0.15` seconds. Assume that in the next `0.15` second interval, just three messages arrive; now Liberator sends the batch of three messages on after `0.15` seconds. But in the next `0.15` second interval, more than three messages arrive, so once Liberator has sent the batch on, it adds `burst-increment` to `batching_interval` again, making a `batching_interval` of `0.2` seconds. Continuing in the same way, every time more than three messages arrive within `batching_interval` seconds, Liberator increments `batching_interval` by `burst-increment` seconds, _up to a maximum value of_ `burst-max` seconds. The `batching_interval` can also be reduced - every time _no_ messages arrive within `batching_interval` seconds, Liberator reduces `batching_interval` by `burst-increment` seconds, down to a minimum value of `burst-min` seconds. --- **See also:** * [About Liberator’s bursting feature](liberator-bursting.md) * [Throttling configuration](liberator-throttling-configuration.md) * [Tuning configuration](liberator-tuning-configuration.md)