# 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". For an explanation of how these configuration items control the amount of bursting, see How bursting works below. **💡 TIP**\ You can also use Liberator’s throttling 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${THIS_LEG}_BURST_MAX` to specify Liberator’s `burst-max` value. Set the macro in the file <Framework-root>/global_config/environment.conf. See Deployment Framework [Configuration macros and items](../deployment-framework/cdf-configuration-macros-and-items.md). **❗ IMPORTANT**\ Don’t batch trade messages. The [no-batching](liberator-object-configuration-part-1.md#no-batching) option of [add-object](liberator-object-configuration-part-1.md#add-object) turns off batching of messages for that object, thus overriding the `burst-min`, `burst-increment` and `burst-max` settings. Set `no-batching` to `TRUE` for objects that define the subjects of trade messages, since trade messages should be propagated to clients with minimum possible latency and so must never be batched. **Syntax:** `burst-max ` **Type:** float **Default value:** `0.5` seconds ## burst-min `burst-min` specifies defines the minimum time in seconds during which messages are batched together before being sent to the client (the batching interval). For an explanation of how `burst-min` works together with [burst-max](#burst-max) and [burst-increment](#burst-increment), see [How bursting works](#how-bursting-works) below. **📌 NOTE**\ In the [Caplin Platform Deployment Framework](../deployment-framework/index.md), you use a configuration macro `LIBERATOR${THIS_LEG}_BURST_MIN` to specify Liberator’s `burst-min` value. Set the macro in the file <Framework-root>/global_config/environment.conf. See Deployment Framework [Configuration macros and items](../deployment-framework/cdf-configuration-macros-and-items.md). **❗ 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)