Opcode (1) : 0x83
Key length (2,3) : 0x0000
Extra length (4) : 0x04
Data type (5) : 0x00
Status (6,7) : 0x0000
Total body (8-11) : 0x00000009
Opaque (12-15): 0x00000000
CAS (16-23): 0x0000000000000001
Extras :
Flags (24-27): 0xdeadbeef
Key : None
Value (28-32): The textual string "World"
{code}
h1. Client API
h2. Java
Note: not sure if we like this yet...
{code}
GetFuture resf;
boolean isReplicaRead;
try {
resf = cbc.asyncGet("foo");
isReplicaRead = false;
} catch (TimeoutException ex) {
// uhoh, something went wrong, server isn't there!
resf = cbc.asyncReplicaGet("foo");
isReplicaRead = true;
} finally {
// do something useful
}
{code}
h2. .NET
h2. PHP
h2. Ruby
{code:none}
res = nil
is_replica_read = false
begin
res = cbc.get("foo")
rescue Couchbase::Error::Timeout => ex
res = cbc.get("foo", :replica => true)
is_replica_read = true
ensure
# do something useful
end
{code}
h1. Recommended Implementation
{note}These recommendations are preliminary, and have not been reviewed.{note}
The replica read command is intentionally simple. It would attempt to iterate through all of the replicas as designated by the configuration supplied by the cluster in order, trying to get the specified key.
h2. Implementation Constraints
{{REPLICA READ}} is a binary protocol only operation. It could be implemented in ASCII, but that would require changes in moxi and additional clients.
h2. Implementation Questions
...