--- BRES 2001/06/21 05:16:05 1.1
+++ BRES 2001/06/28 14:08:00 1.2
@@ -7,6 +7,18 @@
- eXtendable Data Serialization Library: libxds
- Simple Remote Procedure Call Library: libsrpc
+- libxds does intentionally NOT support the concept of arrays and
+ structures ("sequence" and "record" in ASN.1-speak), because not all
+ encoding systems support structured data. Hence, someone who'd want
+ to decode the serialized buffer cannot rely on this information
+ actually being included in the encoded data.
+
+ The only use of having these capabilities nonetheles would be that
+ the decode function could type-check the specification of what has
+ been received against the actual contents of the data. While this is
+ nice to have, we did not consider this to be reason enough to add
+ complexity to our interface and implementation.
+
- The server actually performing the function call has to interpret
the transferred data according to the functions prototype. This may
be done in one of the following ways:
@@ -27,14 +39,14 @@
because
o constant function prototype on server-side
(foreign function call problem!)
- o only application knows how to convert
+ o only application knows how to convert
complex data structures (foo_t) into
serialized octet-stream
o greater flexibility in data transfer
o rpc library complexity is reduced
(on cost of application complexity)
- instead remote procedure call
+ instead remote procedure call
only message passing
- auditing/logging:
@@ -46,7 +58,7 @@
sepatered from data serialization
- error semantics:
- transaction, ACID
+ transaction, ACID
o exactly-once (== 1) bank transaction
o at-least-once (>= 1) muss passieren, mehrfach tut nicht weh (seiteneffekte) SunRPC
o at-most-once (<= 1) logging of not important data, video conferneces
@@ -61,7 +73,7 @@
- asynchronous vs. synchronous
Ideee: intern immer asynchrouns
- aber in API wrapper function
+ aber in API wrapper function
rpc_call == rpc_send+rpc_wait+rpc_result
und auch rpc_abort
trotzdem wird beide male ein timeout vorgesehen
@@ -135,7 +147,7 @@
- Firewalls? Sollen die Filtern koennen
Encryption nur von Data, nicht von Meta-Data
-- Proxies?
+- Proxies?
- Sowohl AMP als auch XDR muessen backends von
Application implementieren lassen!
@@ -153,7 +165,7 @@
- Fail Over
- IPv6 in AMP unterstuetzen
-- Multicasting in AMP unterstuetzen (trivial I/O seitig,
+- Multicasting in AMP unterstuetzen (trivial I/O seitig,
aber muss bei error semantics beruecksichtig werden)
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