NPACI Rocks Cluster Distribution: Reference Guide: 
| ||
|---|---|---|
| Prev | Chapter 4. Internals | Next |
This section describes the SQL Database Schema used by the Rocks system. The free MySQL DBMS server manages the schema in a single database named cluster. This database forms the backbone of the Rocks system, coordinating tasks as diverse as kickstart, node typing, configuration file building, and versioning.
This diagram describes the database relations in a simplified standard notation.
A subset of the Information Engineering (IE) notation method will be used to describe the database tables. Primary keys are marked with an asterisk (*), and foreign keys are designated by (@). Attempts have been made to ensure this schema is at least in the Second Normal Form (2NF).
For each table, we present its structure followed by an explanation of its columns.
Describes nodes in the cluster. A central table in the schema. The nodes table holds one row for each node in the cluster, including frontend, compute, and other appliance types. The node's location in the physical cluster (which rack it lies in on the floor) is specified in this table as well.
Table 4-1. Nodes
| Field | Type |
|---|---|
| ID* | int(11) |
| Name | varchar(128) |
| Membership@ | int(11) |
| CPUs | int(11) |
| Rack | int(11) |
| Rank | int(11) |
| Comment | varchar(128) |
A primary key integer identifier. Auto incremented.
The name of the private network interface for this node. This violates the second normal form (2NF) of the schema (this name should only exist in the networks table), but serves as a hint for readability.
A link to the Memberships table; cannot be null. Specifies what type of node this is.
The number of Processors in this node. Defaults to 1. Although this column violates the second normal form, it is more useful here than in a separate table.
The Y-axis coordinate of this node in euclidean space. Zero is the leftmost rack on the floor by convention. Note we only use a 2D matrix to locate nodes, the plane (Z-axis) is currently always zero.
The X-axis of this node in euclidean space. Zero is closest to the floor (the bottom-most node) by convention.
The IPv4 Internet Protocol address of this node in decimal-dot notation.
A textual comment about this node.
The network interfaces for a node.
Table 4-2. Networks
| Field | Type |
|---|---|
| ID* | int(11) |
| Node@ | int(11) |
| MAC | varchar(32) |
| IP | varchar(32) |
| Netmask | varchar(32) |
| Gateway | varchar(32) |
| Name | varchar(128) |
| Device | varchar(32) |
| Module | varchar(128) |
A primary key integer identifier. Auto incremented.
A link to the nodes table. A foreign key, cannot be null.
The 6-byte Media Access Layer address (Layer 2) of this interface in hex-colon notation like "a6:45:34:0f:44:99".
The IPv4 Internet Protocol address of this interface in decimal-dot notation like "10.255.255.254".
The subnet mask of the IP address. Specified like "255.0.0.0".
The IP gateway or router address for this interface.
The hostname for this network interface. The Rocks convention is "compute-[Rack]-[Rank]" for compute nodes.
If the device name is "eth0" this is the "private" network interface for the node. The interface name is placed in the .local domain and served via DNS. All other hostnames must be fully-qualified.
The Linux device name for this NIC. The private (primary) interface always has the name "eth0".
The Linux device driver name for this interface. Hardware specific.
This table contains Key=Value pairs used for essential services such as Kickstart. Examples include the Keyboard layout, Public Gateway, Public Hostname, DNS servers, IP mask, Cluster Owner, Admin email, etc.
Table 4-3. App_Globals
| Field | Type |
|---|---|
| ID* | int(11) |
| Membership@ | int(11) |
| Service | varchar(64) |
| Component | varchar(64) |
| Value | text |
A primary key integer identifier. Auto incremented.
A foreign key that references the ID column in the Membership table.
The service name that will use this KEY=VALUE pair. Examples are "Kickstart" and "Info". This is essentially the first part of a two-level naming scheme.
The second level name. Together the Service and Component names correspond to the name attribute of the <var name="Service_Component"/> XML tag used in the kickstart generation process.
The value of this row. Can be any textual data.
This table specifies the distribution version and appliance type for a set of nodes. An alternative name for this table would be groups, however that is a reserved word in SQL. The memberships table names a group of nodes in the cluster and allows multiple memberships to tie into one appliance type.
Table 4-4. Memberships
| Field | Type |
|---|---|
| ID* | int(11) |
| Name | varchar(64) |
| Appliance@ | int(11) |
| Distribution@ | int(11) |
| Compute | enum('yes','no') |
A primary key integer identifier. Auto incremented.
The name of this membership. A type of node in the cluster, like "Frontend", "Compute", "Power Unit" or similar. The software installed on nodes in a given membership is defined by an appliance ID.
A foreign key that references the ID column in the Appliances table. Helps define the software installed on nodes in this membership, and therefore their behavior.
A foreign key that references the ID column in the Distributions table. The second key used to define the software for nodes in this membership.
Either "yes" or "no". Specifies whether this type of node will be used to run parallel jobs.
This table defines the available appliance types. Each node in the cluster may classify itself as a single appliance type. The Graph and Node attributes define the starting point in the Rocks software configuration graph (See Graph XML), which wholly specifies the software installed on a node.
Table 4-5. Appliances
| Field | Type |
|---|---|
| ID* | int(11) |
| Name | varchar(32) |
| ShortName | varchar(32) |
| Graph | varchar(64) |
| Node | varchar(64) |
A primary key integer identifier. Auto incremented.
The name of this appliance. Examples are "frontend" and "compute".
A nickname for this appliance.
Specifies which software configuration graph to use when creating the kickstart file for this appliance. The default of default is generally used.
Specifies the name of the root node in the configuration graph to use when creating the kickstart file for this appliance. The software packages for this appliance type is wholly defined by a traversal of the configuration graph beginning at this root node.
This table connects a membership group to a versioned Rocks distribution, and plays an important role in the Rocks kickstart generation process. The Release relates to the RedHat distribution version, e.g. "7.2", while the Name specifies where to find both the Rocks configuration tree and RPM packages. The location of these resources will be under the /home/install/[Name]/[Release]/ directory.
Table 4-6. Distributions
| Field | Type |
|---|---|
| ID* | int(11) |
| Name | varchar(32) |
| Release | varchar(32) |
| Lang | varchar(32) |
A primary key integer identifier. Auto incremented.
Specifies where to find the Rocks configuration tree graph files. The Name field of the configuration graph located in the /home/install/[Name]/[Release]/ directory.
Gives the the RedHat distribution version this configuration tree is based on , e.g. "7.2". The Release field in the graph location "/home/install/[Name]/[Release]/" directory.
The language of this distribution. A two-letter language abbreviation like "en" or "fr".
This table is intended to provide database schema versioning. It is reserved for future use.
The name of a table in this database schema.
The major version number of this table. Usually the first integer in the version string.
The minor version number of this table. The second integer in the version string.
This table contains any user-defined aliases for nodes.
A primary key integer identifier. Auto incremented.
A foreign key that references the ID column in the Nodes table.
The alias name. Usually a shorter version of the hostname.