Index Distribution and the Index Replication Status (SAP Library

Index Distribution and the Index Replication Status

Use

The Index Landscape window displays how the indexes are distributed among the index servers and the status of index replication.

Features

A table displays existing indexes and information on each index. You can find a description of the table columns below.

Columns Index ID through Index Parts

Index ID and index type. The Index Parts column specifies the parts that the index comprises. This column is filled only for logical indexes, compound indexes, and BIA indexes.

Indexer Column

Index server that updates the master index.

The values in this column have the format <traffic_light> <server>, <index_version>. The elements have the following meanings:

Element	Meaning
<light>	Status of the index server that is updating the master index: ● Green Server is available ● Yellow The name server does not know the server status. The server receives this status in the start phase. If the name server can reach the server, it changes the light to green. If not, it changes the light to red. ● Red Server is not available
<server>	Tells you whether the master index server or the backup index server updates the master index.
<index_version>	Version of the master index This number is increased by one every time the master index is updated.

Searcher Column

Index server on which the search takes place.

The values in this column have the format <traffic_light> <server> + <n> of <m> slaves, <index_version>. The elements have the following meanings:

Element	Meaning
<light>	Status of the servers that make the index available. The status tells you whether the servers have started and whether they have the correct index version. ● Green All servers are available ● Yellow Some servers are available ● Red None of the servers are available
<server>	Tells you whether the master index server or the backup index server is used for the search. ● master or backup The master index server or the backup index server is used for the search. This setting is displayed in one of the following situations: ○ The master and backup index servers are not locked for searching. ○ No slave index servers are configured. ● (master) or (backup) The master and backup index servers are locked for searching. However, one of them is being used for searching because none of the slave index servers has the most up-to-date index version.
+ <n> of <m> slaves	Number of slave index servers on which the index version <index_version> is available.
<index_version>	Index version on which TREX is currently searching.

Search Version Column

Setting that is valid for the search. The following settings are possible:

● latest

TREX searches on the most up-to-date index version.

● majority

TREX searches on the index version that is available on most of the index servers.

● master or backup

TREX searches on the master index. The master index server or the backup index server answers the search queries.

This setting is displayed if no slave index servers are configured.

● (master) or (backup)

TREX searches on the master index. The master index server or the backup index server answers the search queries.

This setting is displayed if the master index is locked for searching and TREX is using it anyway. This may be because:

○ The master index has not yet been replicated.

○ The slave index servers are not available.

○ The Search Version parameter has the setting latest. None of the slave index servers has the most up-to-date index version.

Replication State Column

Index replication status

The values in this column have the format <traffic_light> <status>. The elements have the following meanings:

Element

Meaning

Replication status

● Green

No replication is necessary

● Blue

Replication is necessary

● Pink <phase>

The system is currently replicating. <phase> tells you the current phase of the replication:

○ started

Replication has just started.

○ export

The master index server or the backup index server is collecting the changed index files.

○ prepare

TREX is copying the changed index files to the slave index servers.

This phase is only relevant if you are using decentralized data storage.

○ commit

TREX is integrating the changed index files on the slave index servers.

○ queued

Replication cannot be carried out straight away because another index is currently being replicated.

The number of parallel replications is defined in the Replication Threads parameter.

● Red

The last replication failed.

<host_name>:<index_server_port> Column

Information on the individual TREX servers

The column header displays the index server status:

● This graphic is explained in the accompanying text Green or active

Server is available

● This graphic is explained in the accompanying text Yellow or unknown

The name server does not know the server status. The server receives this status in the start phase. If the name server can reach the server, it changes the light to green. If not, it changes the light to red.

● This graphic is explained in the accompanying text Red or inactive

Server is not available

The values in this column have the format <+ | - server_type>, <index_version>. The elements have the following meanings:

Element

Meaning

<+ | - server_type>

Tells you whether the index server is active and what its role is.

● +master or +backup

The index server is active. It is configured as a master index server or a backup index server.

● -master or -backup

The index server is not active.

● +slave

The index server is active (available for searching). It is configured as a slave index server.

● -slave

The index server is not active. This may be because:

○ The index server has not started.

○ The index server is currently integrating the changed index files and is therefore not available for searching.

● -creating

Only with centralized data storage.

The index server is configured as a slave index server and is using an index snapshot as a slave index. No replication has taken place yet, so the index snapshot is not yet available. After the initial replication has taken place the server receives the status +slave.

<index_version>

Index version available on the index server.

Detailed View

The TREX admin tool (stand-alone) provides a standard view and a detailed view of the table. The detailed view of the table displays the following additional information:

● Index description

● Path specifications

● Specifies whether the slave index servers use a common slave index (Shared Slaves = yes) or separate slave indexes (Shared Slaves = no).

You can use Show Details to display the detailed view.