Cisco Cisco Packet Data Interworking Function (PDIF)
HDD Storage
▀ How HDD Works
▄ GTPP Interface Administration and Reference, StarOS Release 18
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CDR Streaming via GTPP
HDD is used to store CDRs when CGF fails and then CDRs are streamed to the CGF when CGF is up. Streaming can be
done in a First-In-First-Out (FIFO) or parallel mode. The parallel mode of operation is newly introduced in release 16.0.
In FIFO mode, newly generated CDRs are routed to CGF via HDD. In parallel mode, newly generated CDRs from
AAA Managers are sent directly to CGF server along with the streamed CDRs from hard disk.
done in a First-In-First-Out (FIFO) or parallel mode. The parallel mode of operation is newly introduced in release 16.0.
In FIFO mode, newly generated CDRs are routed to CGF via HDD. In parallel mode, newly generated CDRs from
AAA Managers are sent directly to CGF server along with the streamed CDRs from hard disk.
With streaming mode enabled, CDRs are written to HDD when the OCG connectivity is down. Once the OCG
connectivity is up, the HDD contents are sent in a FIFO order. New records should be written to disk as long as all
contents from disk are not fully flushed. If the disk is completely flushed, the records can be sent to OCG directly.
connectivity is up, the HDD contents are sent in a FIFO order. New records should be written to disk as long as all
contents from disk are not fully flushed. If the disk is completely flushed, the records can be sent to OCG directly.
In the FIFO implementation, CDR streaming works fine but the process of sending the newly generated CDRs to HDD
and then to CGF is inefficient. Also, if the CDR generation rate is high and streaming rate is slow, the files in HDD will
keep increasing and eventually there will be no space left in hard disk, leading to CDR purging. This can be avoided by
sending the newly generated CDRs directly to CGF when streaming from HDD is in progress.
and then to CGF is inefficient. Also, if the CDR generation rate is high and streaming rate is slow, the files in HDD will
keep increasing and eventually there will be no space left in hard disk, leading to CDR purging. This can be avoided by
sending the newly generated CDRs directly to CGF when streaming from HDD is in progress.
With parallel mode, this behavior is changed to send new CDRs directly to CGF when streaming from HDD is in
progress.
progress.
The existing CLI command “gtpp storage-server mode streaming” used to set the streaming mode, is extended. The
“
“
parallel
” keyword used with this command enables the new parallel streaming mode.
In the current implementation, during streaming, GTPP requests are read from HDD and sent to CGF server, till
configured max outstanding is reached.
configured max outstanding is reached.
In PARALLEL mode, rate of streaming from HDD will be slow. It is assumed that the billing domain should be capable
of handling Out-Of-Order CDRs in parallel streaming mode.
of handling Out-Of-Order CDRs in parallel streaming mode.
CDR Streaming Workflow
This section describes the streaming behavior in Streaming (FIFO) and Parallel mode.
CGF is reachable, No files in HDD:
FIFO: newly generated CDRs will be sent to CGF server.
Parallel: newly generated CDRs will be sent to CGF server.
CGF server is not reachable:
FIFO: newly generated CDRs will be stored to HDD.
Parallel: newly generated CDRs will be stored to HDD
CGF is not reachable, HDD has less than 3 files, Now CGF becomes active:
FIFO: AAAMgr is blocked from sending new CDRs. GTPP requests in HDD are first streamed out to CGF
server. After all requests in HDD are flushed, start sending new CDRs to CGF.
server. After all requests in HDD are flushed, start sending new CDRs to CGF.
Parallel: Same behavior as in FIFO mode.
CGF is not reachable, HDD has 3 or more CDR files, Now CGF becomes active:
FIFO: GTPP requests in HDD are streamed to CGF server. Newly generated CDRs will be stored in HDD and
then sent to CGF
then sent to CGF
Parallel: GTPP requests in HDD are streamed to CGF server at a slower pace. Newly generated CDRs will be
sent directly to CGF server.
sent directly to CGF server.