Contents
Note
The adapter uses the libpcap (Linux) and WinPcap (Windows) libraries to tap into the IP packet stream.
Before using this adapter with realtime data, you must install and configure these
libraries on the system that will host the HTTP Reader adapter. Locate libpcap at http://www.tcpdump.org/ and
WinPcap at http://www.winpcap.org.
The HTTP reader input adapter reads Internet Protocol packets, either from the IP stack of a running system or from an archived capture file, and emits a tuple for each HTTP message found in the TCP data stream. Dedicated tuple fields hold the request and response messages, the HTTP headers (Authorization, From, Referrer, Content-Length, User-Agent, and so on.), and the request and response body of the message. When reading IP traffic on a running system, a filter string can be configured to limit the IP traffic being read. The adapter uses the libpcap (Linux) and WinPcap (Windows) libraries to tap into the IP packet stream.
Note
This adapter is not provided in the StreamBase kit, but is made available in a separate installation kit. Please contact StreamBase Systems if you are interested in the kit.
| Property | Description |
|---|---|
| Data Source | Select Realtime Data or Capture File to read HTTP traffic from the IP stack of a running system or from an archived capture file, respectively. |
| Network Interface IP Address | IP address of the network interface to read HTTP traffic from the IP stack of a running system or leave empty to use any available interface. |
| Capture File Name |
The fully-qualified name of the capture file holding the IP packets to
process. The capture file must be on a libpcap- or WinPcap-compatibile
format. The property is ignored when Data
Source is set to Realtime Data.
|
| TCP Port Number | The well-known TCP port number of HTTP server, which defaults to 80. |
| Capture Filter String | A libpcap- or WinPcap-compatible filter string that can be used to limit the IP traffic being read. |
| Schema (schema) |
The schema to output, which must include the following fields, which the
adapter automatically creates. The user can override the length of any string
field by adding that field in Studio's Edit Schema tab:
|
Schema fields entered in Studio's Edit Schema tab not listed above, or of type other than string and blob, cause a typecheck error to be thrown.
A tuple is emitted only when a complete HTTP request and response message is detected in the TCP stream. If one or more IP packets are missing such that the TCP stream cannot be reconstructed, no tuple is emitted for the corresponding HTTP message.
When suspended, the adapter stops processing IP packets. Note that doing so may cause the libpcap or WinPcap libries to discard IP packets, resulting in lost tuples when the adapter is eventually resumed.
