China Grid and Related Dependability Research - Grid Computing: Infrastructure, Service, and Applications - page 90

TABLE 4.1
Five Basic Packet Types Implemented in CGSV Protocol
Type

Packet Example Purpose Comments

QUERY (QUERY (get

1.2.3.4*))

Issue a data query
request for all
measurement data
of host 1.2.3.4

If this IP is a cluster,
all back-end nodes'
information are
returned

DATA (DATA(hostname

1.2.3.4)(timestamp
1115715626)
(OSType 1 10)
(CPUNumber
2 10))

Data packet indicating
2 monitor items
(OS type and CPU
number) with host IP
and collect time

Metric information
tuple is composed
metric name, value
and time difference
with the complete
timestamp.

SCHEMA (SCHEMA

(hostname 1.2.3.4)
(OSType 1 1500)
(CPULoad 0 15))

Schema packet
indicating 2 metrics
are supported on
host 1.2.3.4 with
their switches and
monitor intervals

Metric schema tuple
is composed the
name switch l ag
and monitor interval
in seconds

CTRL (CTRL (close

1.2.3.4 4))

Issue a control request
to switch MemFree
metric off on host
1.2.3.4

“4” is predei ned
number for MemFree
metric, full metric
name is also accepted

RESULT (RESULT (1

(get 1.2.3.4 *)))

Indicates execution
result (1) of command
“get 1.2.3.4 *”

“1” is predei ned
error code for
success

services are deployed. Registry of CGSV performs two tasks. One
is to provide a lookup service for consumers to locate producer/
republisher registration; the other is to store producers' metric
schema for system extension and modii cation. Since the adaptable
implementation of sensors and protocol allows producers to
accept control packets from any trusted source, the schema held
by the registry needs to be synchronized periodically.
Archive: Archiving is an optional component. It periodically •

acquires measurement data from all data sources and stores them
as historical information in DBMS. This mechanism works similarly
to registry schema synchronization. The difference is that the
archive needs more resources, such as storage, so a distributed
DBMS is used to share the loads when the domain grows larger.
Services and message gateway: Domain monitor services are

•

WSRF-compliant services that are responsible for providing
monitoring information and management information interfaces.
WSDM specii cation has been studied and applied to monitoring
services for management issues. Each domain is treated as a
WSDM manageability capability.