GlossaryΒΆ
- cache span
- The physical storage described by a single line in storage.config.
- cache stripe
- A homogenous persistent store for the cache in a single cache span. A stripe always resides entirely on a single physical device and is treated as an undifferentiated span of bytes.
- cache volume
- A user defined unit of persistent storage for the cache. Cache volumes are defined in volume.config. A cache volume is by default spread across cache spans to increase robustness. Each section of a cache volume on a specific cache span is a cache stripe.
- continuation
- A callable object that contains state. These are are mechanism used by Traffic Server to implement callbacks and continued computations. Continued computations are critical to efficient processing of traffic because by avoiding any blocking operations that wait on external events. In any such case a continuation is used so that other processing can continue until the external event occurs. At that point the continuation is invoked to continue the suspended processing. This can be considered similar to co-routines.
- revalidation
- Verifying that a currently cached object is still valid. This is usually done using an If-Modified-Since request which allows the origin server to validate the content without resending the content.
- session
- A single connection from a client to Traffic Server, covering all requests and responses on that connection. A session starts when the client connection opens, and ends when the connection closes.
- storage unit
- Obsolete term for cache span.
- transaction
- A client request and response, either from the origin server or from the cache. A transaction begins when Traffic Server receives a request, and ends when Traffic Server sends the response.
- write cursor
- The location in a cache stripe where new data is written.