Distributed James Server — cassandra.properties
This configuration file allow setting some configuration properties in conjunction to Cassandra driver native configuration.
Consult this example to get some examples and hints.
Consult this example to get some examples and hints for Cassandra driver native configuration.
Cassandra native configuration allows configuring SSL, timeouts, logs and metrics as well as execution profiles.
Configuration
Here are generic properties:
Property name | explanation |
---|---|
cassandra.nodes |
List of some nodes of the cassandra’s cluster in following format host:port or host, if the port is not specified we use 9042 |
cassandra.keyspace.create |
Indicate if the keyspace should be created by James. Optional, default value: false If set to true James will attempt to create the keyspace when starting up. |
cassandra.keyspace |
Is the name of the keyspace used by James. Optional, default value: apache_james |
cassandra.user |
Username used as a credential for contacting Cassandra cluster. Optional, default is absent, required if cassandra.password is supplied |
cassandra.password |
Password used as a credential for contacting Cassandra cluster. Optional, default is absent, required if <strong>cassandra.user</strong> is supplied |
cassandra.replication.factor |
Is the replication factor used upon keyspace creation. Modifying this property while the keyspace already exists will have no effect. Optional. Default value 1. |
cassandra.local.dc |
Optional. Allows specifying the local DC as part of the load balancing policy. Specifying it
would result in the use of |
optimistic.consistency.level.enabled |
Optional. Allows specifying consistency level ONE for reads in Cassandra BlobStore. Falls back to default read consistency level if the blob is missing. Defaults to false. |
Cassandra Mailbox Configuration
cassandra.properties file furthermore expose some options to tune the Cassandra Mailbox behaviour.
Property name | explanation |
---|---|
mailbox.read.repair.chance |
Optional. Defaults to 0.1 (10% chance). Must be between 0 and 1 (inclusive). Controls the probability of doing a read-repair upon mailbox read. |
mailbox.read.repair.chance |
Optional. Defaults to 0.1 (10% chance). Must be between 0 and 1 (inclusive). Controls the probability of doing a read-repair upon mailbox read. |
mailbox.counters.read.repair.chance.max |
Optional. Defaults to 0.1 (10% chance). Must be between 0 and 1 (inclusive). Controls the probability of doing a read-repair upon mailbox counters read. Formula: read_repair_chance = min(mailbox.counters.read.repair.chance.max, (100/unseens)*mailbox.counters.read.repair.chance.one.hundred) |
mailbox.counters.read.repair.chance.one.hundred |
Optional. Defaults to 0.01 (1% chance). Must be between 0 and 1 (inclusive). Controls the probability of doing a read-repair upon mailbox counters read. Formula: read_repair_chance = min(mailbox.counters.read.repair.chance.max, (100/unseens)*mailbox.counters.read.repair.chance.one.hundred) |
mailbox.max.retry.acl |
Optional. Defaults to 1000. Controls the number of retries upon Cassandra ACL updates. |
mailbox.max.retry.modseq |
Optional. Defaults to 100000. Controls the number of retries upon Cassandra ModSeq generation. |
mailbox.max.retry.uid |
Optional. Defaults to 100000. Controls the number of retries upon Cassandra Uid generation. |
mailbox.max.retry.message.flags.update |
Optional. Defaults to 1000. Controls the number of retries upon Cassandra flags update, in MessageMapper. |
mailbox.max.retry.message.id.flags.update |
Optional. Defaults to 1000. Controls the number of retries upon Cassandra flags update, in MessageIdMapper. |
chunk.size.message.read |
Optional. Defaults to 100. Controls the number of messages to be retrieved in parallel. |
mailbox.blob.part.size |
Optional. Defaults to 102400 (100KB). Controls the size of blob parts used to store messages in the Cassandra blobStore. |
mailbox.read.strong.consistency |
Optional. Boolean, defaults to true. Disabling should be considered experimental. If enabled, regular consistency level is used for read transactions for mailbox. Not doing so might result in stale reads as the system.paxos table will not be checked for latest updates. Better performance are expected by turning it off. Note that reads performed as part of write transactions are always performed with a strong consistency. |
uid.read.strong.consistency.unsafe |
Optional. Boolean, defaults to true. Disabling should be considered experimental. If enabled, regular consistency level is used for read transactions for uid upon read oepration (eg IMAP status, select). Not doing so might result in stale reads as the system.paxos table will not be checked for latest updates. Better performance are expected by turning it off. Note that reads performed as part of write transactions are always performed with a strong consistency. |
modseq.read.strong.consistency.unsafe |
Optional. Boolean, defaults to true. Disabling should be considered experimental. If enabled, regular consistency level is used for read transactions for modseq upon read operation (eg IMAP status, select). Not doing so might result in stale reads as the system.paxos table will not be checked for latest updates. Better performance are expected by turning it off. Note that reads performed as part of write transactions are always performed with a strong consistency. |
message.read.strong.consistency |
Optional. Boolean, defaults to true. Disabling should be considered experimental. If enabled, regular consistency level is used for read transactions for message. Not doing so might result in stale reads as the system.paxos table will not be checked for latest updates. Better performance are expected by turning it off. Note that reads performed as part of write transactions are always performed with a strong consistency. |
message.write.strong.consistency.unsafe |
Optional. Boolean, defaults to true. Disabling should be considered experimental and unsafe.
If disabled, Lightweight transactions will no longer be used upon messages operation (table |
mailrepository.strong.consistency |
Optional. Boolean, defaults to true. Allows not to use lightweight transactions in CassandraMailRepository. If disabled we implement an idempotent behaviour (duplicates are overridden, missing entries upon deletes are ignored). |
acl.enabled |
Optional. Boolean, defaults to true. Allows disabling ACLs: if set to false, delegation will fail and users will only have access to the mailboxes they own. ACLs can represent a high volume of requests. If you do not propose mailbox sharing features to your users, you can consider disabling them in order to improve performance. |