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NataliaIvakinaNataliaIvakina
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Clarify situation when enabling newly added servers
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‎modules/ROOT/pages/changes-deprecations-removals.adoc‎

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Original file line numberDiff line numberDiff line change
@@ -143,7 +143,7 @@ Instead use the value of xref:configuration/configuration-settings.adoc#config_s
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Instead use the value of xref:configuration/configuration-settings.adoc#config_server.cluster.listen_address[`server.cluster.listen_address`].
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|link:{neo4j-docs-base-uri}/operations-manual/5/configuration/configuration-settings#config_server.groups[server.groups] label:enterprise[Enterprise Edition]
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|Replaced by xref:configuration/configuration-settings.adoc#config_server.tags[`initial.server.tags`].
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|Replaced by xref:configuration/configuration-settings.adoc#config_initial.server.tags[`initial.server.tags`].
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|link:{neo4j-docs-base-uri}/operations-manual/5/configuration/configuration-settings#config_server.memory.off_heap.block_cache_size[server.memory.off_heap.block_cache_size]
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|Removed without replacement.

‎modules/ROOT/pages/clustering/multi-region-deployment/multi-data-center-routing.adoc‎

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@@ -57,7 +57,7 @@ Applying the same tag to multiple servers logically groups them together.
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Note that servers can have mulitple tags.
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Server tags are defined as a key that maps onto a set of servers in a cluster.
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Server tags are defined on each server using the xref:configuration/configuration-settings.adoc#config_server.tags[`initial.server.tags`] parameter in _neo4j.conf_.
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Server tags are defined on each server using the xref:configuration/configuration-settings.adoc#config_initial.server.tags[`initial.server.tags`] parameter in _neo4j.conf_.
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Each server in a cluster can be tagged with to zero or more server tags.
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Server tags can be altered at runtime via the `ALTER SERVER` command,
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see xref:clustering/servers.adoc#alter-server-options[Altering server options] for more details.

‎modules/ROOT/pages/clustering/servers.adoc‎

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@@ -37,8 +37,19 @@ When first discovered, a server's name defaults to the value of its generated se
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[[server-enabled-state]]
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=== Enabled state
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A server in the free state needs to be explicitly enabled in order to be considered an active member of the cluster.
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The command `ENABLE SERVER server name` is used to transition a server into this _Enabled_ state.
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When you deploy a cluster for the first time, all servers included in the initial deployment are automatically enabled.
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For details, refer to the example on how to xref:clustering/setup/deploy.adoc#cluster-example-configure-a-three-primary-cluster[Configure a cluster with three servers].
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If you add a new server after the cluster is already running, the server is added in the `FREE` state.
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A server in the `FREE` state needs to be explicitly enabled in order to be considered an active member of the cluster.
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To transition a server into the _Enabled_ state, use the command `ENABLE SERVER`:
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[source, syntax, role=noheader]
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----
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ENABLE SERVER 'serverId' [OPTIONS "{" option: value[,...] "}"]
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----
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The server's initial name is its ID.
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If the server is already enabled and the command is executed with the same options, nothing is changed.
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@@ -72,11 +83,22 @@ This may not be specified in combination with `allowedDatabases`.
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[NOTE]
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====
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When a server is enabled, if no `OPTIONS` are not provided, the default server values are taken from the settings `initial.server.mode_constraint`, `initial.server.allowed_databases`, `initial.server.denied_databases`, and/or `initial.server.tags`.
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When a server is enabled, if no `OPTIONS` are not provided, the default server's values are taken from the settings:
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* xref:configuration/configuration-settings.adoc#config_initial.server.mode_constraint[`initial.server.mode_constraint`]
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* xref:configuration/configuration-settings.adoc#config_initial.server.allowed_databases[`initial.server.allowed_databases`]
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* xref:configuration/configuration-settings.adoc#config_initial.server.denied_databases[`initial.server.denied_databases`]
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* and/or xref:configuration/configuration-settings.adoc#config_initial.server.tags[`initial.server.tags`]
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All these settings are only effective on the first startup of the DBMS.
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====
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Another option to enable a server is to set xref:configuration/configuration-settings.adoc#config_initial.dbms.automatically_enable_free_servers[`initial.dbms.automatically_enable_free_servers`] to `true`.
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Once enabled, the server may be allocated databases to host.
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If you need to change some of the server's values, use the <<alter-server-options, `ALTER SERVER`>> command.
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[[deallocating-state]]

‎modules/ROOT/pages/clustering/setup/analytics-cluster.adoc‎

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@@ -16,44 +16,43 @@ Bear in mind that the GDS library does **not** support fault tolerance and there
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=== Deploy the cluster
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.Configure a cluster with five servers, two only for read queries
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In this example, three servers named `server01.example.com`, `server02.example.com` and `server03.example.com` are configured as the transactional part of the cluster.
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. Configure a cluster with five servers, two only for read queries
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+
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In this example, three servers named `server01.example.com`, `server02.example.com`, and `server03.example.com` are configured as the transactional part of the cluster.
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Two more servers names `server04.example.com` and `server05.example.com` are configured for the analytical queries.
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Neo4j Enterprise Edition is installed on all five servers.
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They are configured by preparing xref:configuration/file-locations.adoc[_neo4j.conf_] on each server.
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+
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Key points:
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+
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* All servers include _all_ members in their discovery list.
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* The servers for analytics have mode constraints configured that restrict their hosting mode to _secondary_ to prevent them from participating in normal write operations.
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* The servers for analytics have their mode constraints configured to _SECONDARY_ to prevent them from participating in write operations.
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* In the example below, you set `dbms.cluster.discovery.resolver_type=LIST`.
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+
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._neo4j.conf_ on server01.example.com:
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[source, properties]
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----
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server.default_listen_address=0.0.0.0
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server.default_advertised_address=server01.example.com
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dbms.cluster.endpoints=server01.example.com:6000,server02.example.com:6000,server03.example.com:6000,server04.example.com:6000,server05.example.com:6000
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----
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+
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._neo4j.conf_ on server02.example.com:
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[source, properties]
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----
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server.default_listen_address=0.0.0.0
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server.default_advertised_address=server02.example.com
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dbms.cluster.endpoints=server01.example.com:6000,server02.example.com:6000,server03.example.com:6000,server04.example.com:6000,server05.example.com:6000
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----
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+
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._neo4j.conf_ on server03.example.com:
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[source, properties]
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----
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server.default_listen_address=0.0.0.0
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server.default_advertised_address=server03.example.com
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dbms.cluster.endpoints=server01.example.com:6000,server02.example.com:6000,server03.example.com:6000,server04.example.com:6000,server05.example.com:6000
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----
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+
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._neo4j.conf_ on server04.example.com - an analytics server:
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[source, properties]
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----
@@ -63,7 +62,7 @@ dbms.cluster.endpoints=server01.example.com:6000,server02.example.com:6000,serve
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initial.server.mode_constraint=SECONDARY
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server.cluster.system_database_mode=SECONDARY
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----
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+
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._neo4j.conf_ on server05.example.com - an analytics server:
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[source, properties]
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----
@@ -74,37 +73,37 @@ initial.server.mode_constraint=SECONDARY
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server.cluster.system_database_mode=SECONDARY
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----
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77-
The Neo4j servers are ready to be started.
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. The Neo4j servers are ready to be started.
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The startup order does not matter.
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80-
After the cluster has started, it is possible to connect to any of the instances and run `SHOW SERVERS` to check the status of the cluster.
79+
. After the cluster has started, it is possible to connect to any of the instances and run `SHOW SERVERS` to check the status of the cluster.
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This shows information about each member of the cluster:
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+
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[source, cypher, role=noplay]
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----
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SHOW SERVERS;
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----
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+
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[queryresult]
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----
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+-----------------------------------------------------------------------------------------------------------+
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| name | address | state | health | hosting |
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+-----------------------------------------------------------------------------------------------------------+
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+----------------------------------------------------------------------------------------------------------+
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| name | address | state | health | hosting |
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+----------------------------------------------------------------------------------------------------------+
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| "f3bd1199-bc6f-4a38-b25c-5f7588df5182" | "server01:7687" | "Enabled" | "Available" | ["system", "neo4j"] |
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| "b331e481-c2ba-4b4e-82f3-bb51fe171483" | "server02:7687" | "Enabled" | "Available" | ["system"] |
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| "bd80e8fd-a51b-406a-9ed4-42daf4792aa6" | "server03:7687" | "Enabled" | "Available" | ["system"] |
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| "df3758b1-337f-4b8a-a9de-8e745ca96549" | "server04:7687" | "Free" | "Available" | ["system"] |
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| "9207bfd9-aa1b-40c2-b965-edcd3955a20e" | "server05:7687" | "Free" | "Available" | ["system"] |
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+-----------------------------------------------------------------------------------------------------------+
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+----------------------------------------------------------------------------------------------------------+
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----
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+
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For more extensive information about each server, use the `SHOW SERVERS YIELD *` command:
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[source, cypher, role=noplay]
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----
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SHOW SERVERS YIELD *;
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----
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+
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[queryresult]
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----
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+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
@@ -118,6 +117,30 @@ SHOW SERVERS YIELD *;
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+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
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----
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. To support analytic queries on the secondary servers, you have to explicitly enable them by running:
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+
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[source, cypher, role=noplay]
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----
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ENABLE SERVER "df3758b1-337f-4b8a-a9de-8e745ca96549";
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ENABLE SERVER "9207bfd9-aa1b-40c2-b965-edcd3955a20e";
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----
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+
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To check the result, run `SHOW SERVERS`.
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The output should show:
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+
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[queryresult]
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----
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+----------------------------------------------------------------------------------------------------------+
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| name | address | state | health | hosting |
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+----------------------------------------------------------------------------------------------------------+
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| "f3bd1199-bc6f-4a38-b25c-5f7588df5182" | "server01:7687" | "Enabled" | "Available" | ["system", "neo4j"] |
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| "b331e481-c2ba-4b4e-82f3-bb51fe171483" | "server02:7687" | "Enabled" | "Available" | ["system"] |
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| "bd80e8fd-a51b-406a-9ed4-42daf4792aa6" | "server03:7687" | "Enabled" | "Available" | ["system"] |
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| "df3758b1-337f-4b8a-a9de-8e745ca96549" | "server04:7687" | "Enabled" | "Available" | ["system"] |
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| "9207bfd9-aa1b-40c2-b965-edcd3955a20e" | "server05:7687" | "Enabled" | "Available" | ["system"] |
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+----------------------------------------------------------------------------------------------------------+
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----
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[[cluster-example-create-databases-on-cluster]]
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=== Create new databases in the cluster
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=== Deploy the cluster
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156-
.Configure a cluster with three servers
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. Configure a cluster with three servers
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+
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In this example, three servers named `server01.example.com`, `server02.example.com` and `server03.example.com` are configured.
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Neo4j Enterprise Edition is installed on all three servers.
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They are configured by preparing xref:configuration/file-locations.adoc[_neo4j.conf_] on each server.
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Note that `server01.example.com` is different from the others, and is the only server where write operations take place.
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The other servers are able to execute read queries, and if using GDS, to write results back to the writing server.
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Key points:
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166189
* The writer server only has itself in the list of discovery.
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This means it does not seek out the other members when it starts, they have to discover it.
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This is required in order to have a cluster with only a single primary for the `system` database.
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* The servers for analytics have mode constraints configured that restrict their hosting mode to _secondary_ to prevent them from participating in normal write operations.
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* The servers for analytics have their mode constraints configured to `SECONDARY` to prevent them from participating in write operations.
170193
* In the example below, you set `dbms.cluster.discovery.resolver_type=LIST`.
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+
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._neo4j.conf_ on server01.example.com - the writer:
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[source, properties]
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----
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# Only has self in this list
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dbms.cluster.endpoints=server01.example.com:6000
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----
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+
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._neo4j.conf_ on server02.example.com - an analytics server:
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[source, properties]
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187210
initial.server.mode_constraint=SECONDARY
188211
server.cluster.system_database_mode=SECONDARY
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----
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+
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._neo4j.conf_ on server03.example.com - an analytics server:
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[source, properties]
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----
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198221
server.cluster.system_database_mode=SECONDARY
199222
----
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The Neo4j servers are ready to be started.
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. The Neo4j servers are ready to be started.
202225
The startup order does not matter.
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204-
After the cluster has started, it is possible to connect to any of the instances and run `SHOW SERVERS` to check the status of the cluster.
227+
. After the cluster has started, it is possible to connect to any of the instances and run `SHOW SERVERS` to check the status of the cluster.
205228
This shows information about each member of the cluster:
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+
207230
[source, cypher, role=noplay]
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----
209232
SHOW SERVERS;
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----
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+
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[queryresult]
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----
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+-----------------------------------------------------------------------------------------------------------+
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| name | address | state | health | hosting |
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+-----------------------------------------------------------------------------------------------------------+
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+----------------------------------------------------------------------------------------------------------+
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| name | address | state | health | hosting |
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+----------------------------------------------------------------------------------------------------------+
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| "d6fbe54b-0c6a-4959-9bcb-dcbbe80262a4" | "server01:7687" | "Enabled" | "Available" | ["system", "neo4j"] |
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| "e56b49ea-243f-11ed-861d-0242ac120002" | "server02:7687" | "Free" | "Available" | ["system"] |
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| "73e9a990-0a97-4a09-91e9-622bf0b239a4" | "server03:7687" | "Free" | "Available" | ["system"] |
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+-----------------------------------------------------------------------------------------------------------+
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+----------------------------------------------------------------------------------------------------------+
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----
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+
223246
For more extensive information about each server, use the `SHOW SERVERS YIELD *` command:
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+
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[source, cypher, role=noplay]
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----
227250
SHOW SERVERS YIELD *;
228251
----
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+
230253
[queryresult]
231254
----
232255
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
@@ -238,6 +261,29 @@ SHOW SERVERS YIELD *;
238261
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
239262
----
240263

264+
. To support analytic queries on the secondary servers, you need to explicitly enable them by running:
265+
+
266+
[source, cypher, role=noplay]
267+
----
268+
ENABLE SERVER "e56b49ea-243f-11ed-861d-0242ac120002";
269+
ENABLE SERVER "73e9a990-0a97-4a09-91e9-622bf0b239a4";
270+
----
271+
+
272+
To check the result, run `SHOW SERVERS`.
273+
The output should show:
274+
+
275+
[queryresult]
276+
----
277+
+----------------------------------------------------------------------------------------------------------+
278+
| name | address | state | health | hosting |
279+
+----------------------------------------------------------------------------------------------------------+
280+
| "d6fbe54b-0c6a-4959-9bcb-dcbbe80262a4" | "server01:7687" | "Enabled" | "Available" | ["system", "neo4j"] |
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| "e56b49ea-243f-11ed-861d-0242ac120002" | "server02:7687" | "Enabled" | "Available" | ["system"] |
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| "73e9a990-0a97-4a09-91e9-622bf0b239a4" | "server03:7687" | "Enabled" | "Available" | ["system"] |
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+----------------------------------------------------------------------------------------------------------+
284+
----
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[[cluster-example-create-databases-on-single-primary-cluster]]
243289
=== Create new databases in the cluster

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