MICROSTRATEGY
INTELLIGENCE SERVER CLUSTERING
What information is shared by the application
across MicroStrategy Intelligence Server nodes?
Report
caches are shared in a cluster and Object caches on each MicroStrategy
Intelligence Server node are synchronized.
Is a
copy of each report cache retained in each MicroStrategy Intelligence Server
node?
No.
Each MicroStrategy Intelligence Server retains a lookup table with information
about the existence and location of report caches. When a cluster node creates
a report cache, information about the location of the new cache is shared with
the other cluster nodes. Each cluster node then updates its own lookup table
with the location of the new cache.
If a
MicroStrategy Intelligence Server node crashes, will report caches be lost?
Although
report caches will not be lost, access to report caches may be affected,
depending on the way in which the report cache is configured.
If a
separate file server is used as a common report cache repository for all
MicroStrategy Intelligence Server cluster nodes, then the loss of a cluster
node will not affect access to the report cache by other nodes.
If the
cluster is configured such that each node locally hosts the report cache
created by that node, then those report caches residing in the lost node will
naturally be inaccessible. If any report cached in that lost node is requested,
then another node within the cluster will re-run and re-cache the report. When
the cluster node is recovered and rejoined into the cluster, all report caches
in that cluster node will be made available again to the rest of the cluster.
If a MicroStrategy Intelligence Server node is
removed from a cluster manually, will report caches be lost?
If an
administrator removes a cluster node from a cluster, then all report caches
that had been created by that cluster node will be inaccessible by the rest of
the cluster, whether or not a separate file server is used as a common report
cache. This behavior is by design.
How
does MicroStrategy Intelligence Server 7.0 clustering enable cache sharing?
Each
node in a MicroStrategy Intelligence Server 7.0 cluster maintains indices of
the caches available on the different nodes. When a report is submitted, these
indices will be searched and once an existing cache is found (in any nodes),
the cached results will be retrieved directly from cache locations in either
the local or remote machine.
What methods can be used to guarantee
availability of the MicroStrategy Intelligence Server report cache?
To
prevent the loss of a MicroStrategy Intelligence Server cluster node from
affecting report cache availability, the cluster can be configured such that a
separate file server is used as a common report cache repository. In order to
maintain cache availability, this separate file server can be configured for
failover with third-party clustering software.
If a report cache is created by a
MicroStrategy Intelligence Server cluster node, will that report cache be seen
in the Cache Monitor of another cluster node?
No.
Although the new report cache will be available for use by other cluster nodes,
the cache will not appear in the Cache Monitor of other cluster nodes. In order
to see all report caches within a cluster, the administrator will need to
create a separate data source within Desktop for each cluster node. Then, the
report caches within each node can be administered separately, using the same
instance of the MicroStrategy Desktop application.
If objects are created, modified or deleted,
will the change be reflected across all MicroStrategy Intelligence Server
cluster nodes?
Yes.
Object caches are synchronized across all cluster nodes. If any change
affecting the Metadata is made by one cluster node, then the cluster node
broadcasts the change to the other cluster nodes. The other cluster nodes will
then update their local object caches.
NOTE:
Client-side object caches will not be automatically be refreshed. In
MicroStrategy Desktop, for example, a user may have to explicitly click on
'Refresh' to see an object change be reflected in the client application.
Should all MicroStrategy Intelligence Server
cluster nodes be configured identically?
Technically,
MicroStrategy Intelligence Servers in a cluster do not have to be configured
identically. The only technical requirements are that all MicroStrategy
Intelligence Servers point to the same metadata and that all MicroStrategy
Intelligence Servers have the same projects registered and in the same state
(i.e., if Node A has Project A in a 'Loaded' state, then Node B must also have
Project A in a 'Loaded' state.).
However,
in order to ease administration and to reduce the risk of unbalanced load
across cluster nodes, it is recommended that all nodes use the same
MicroStrategy Intelligence Server definition and that each machine shows
identical characteristics (i.e., equal RAM, hard disk space, CPU).
Is it possible for different nodes of a
MicroStrategy Intelligence Server cluster to run against different metadata
repositories?
No, all
the nodes in the same cluster must run against the same metadata.
Is it
possible for different nodes of a MicroStrategy Intelligence Server cluster to
run with different configuration settings under the same metadata repository?
Yes
this is possible, using caution because users can configure different nodes at
different settings. For example, differences in memory allocation for the
cache, time out settings, etc can result in uneven performance across cluster
nodes.
What communication protocol does MicroStrategy
Intelligence Server use for intracluster communication?
MicroStrategy
Intelligence Server 7.0 and MicroStrategy Intelligence Server 7.0 SP1 use
TCP/IP when communicating between clusters. MicroStrategy Intelligence Server
7.1 will provide the option of using TCP/IP or UDP/IP (Universal Datagram
Protocol). In 7.2, UDP support was removed as packet loss affects cluster
synchronization.
If a MicroStrategy Intelligence Server cluster
node is rebooted, will the node rejoin the cluster automatically?
Whenever
a MicroStrategy Intelligence Server cluster node is stopped in any way besides
explicitly shutting down the MicroStrategy Intelligence Server service, the
node will automatically rejoin the cluster when the MicroStrategy Intelligence
Server service is restarted. So, if the node crashes, then the node will rejoin
the cluster automatically upon startup.
NOTE:
All cluster nodes must have the same projects loaded. Therefore, MicroStrategy
Intelligence Server must be configured to have the appropriate projects
automatically load upon startup so that the node can successfully rejoin the
cluster upon startup.
If the
cluster node is stopped by explicitly shutting down the MicroStrategy
Intelligence Server service (either through the MicroStrategy Desktop
interface, the Windows Services window, or the MicroStrategy Service Manager),
then the administrator must manually add the node back to the cluster when the
node is restarted. This is by design. Since stopping the MicroStrategy
Intelligence Server service requires intervention of the administrator, this
behavior allows administrators to retain control over the MicroStrategy
Intelligence Server application when the application is restarted.
Does MicroStrategy Intelligence Server support
clustering via Microsoft Cluster Server or any other third-party clustering
software?
Microsoft
Cluster Server (MSCS) can be used for failover of MicroStrategy Intelligence
Server. However, MSCS and other third-party clustering software will not
provide the load-balancing and some of the failover capabilities of
MicroStrategy Intelligence Server's native clustering solution.
Is it possible to run multiple instances of
MicroStrategy Intelligence Server on the same Microsoft Windows NT machine?
MicroStrategy
7.0 does not support running multiple instances of MicroStrategy Intelligence
Server on the same Microsoft Windows NT machine. This is because MicroStrategy
Intelligence Server can support running multiple projects with different
prioritization and configuration settings on one server. This functionality was
not available in MicroStrategy DSS Server 5.x and thus, required running
multiple instances of MicroStrategy Intelligence Server to accomplish the same
functionality.
What is the maximum number of nodes that can
be supported in a MicroStrategy Intelligence Server 7.0 cluster?
There
is no technical hard limit on the maximum number of cluster nodes that can be
supported by MicroStrategy Intelligence Server 7.0. However, when the number of
nodes increases, there is increasing overhead put on the system by the
clustering software. So, there will be practical limits related to the hardware
configuration of the users' system.
No comments:
Post a Comment