org.apache.kafka.common.config.TopicConfig Maven / Gradle / Ivy
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package org.apache.kafka.common.config;
/**
* Keys that can be used to configure a topic. These keys are useful when creating or reconfiguring a
* topic using the AdminClient.
*
*
The intended pattern is for broker configs to include a `log.` prefix. For example, to set the default broker
* cleanup policy, one would set log.cleanup.policy instead of cleanup.policy. Unfortunately, there are many cases
* where this pattern is not followed.
*/
// This is a public API, so we should not remove or alter keys without a discussion and a deprecation period.
// Eventually this should replace LogConfig.scala.
public class TopicConfig {
public static final String SEGMENT_BYTES_CONFIG = "segment.bytes";
public static final String SEGMENT_BYTES_DOC = "This configuration controls the segment file size for " +
"the log. Retention and cleaning is always done a file at a time so a larger segment size means " +
"fewer files but less granular control over retention.";
public static final String SEGMENT_MS_CONFIG = "segment.ms";
public static final String SEGMENT_MS_DOC = "This configuration controls the period of time after " +
"which Kafka will force the log to roll even if the segment file isn't full to ensure that retention " +
"can delete or compact old data.";
public static final String SEGMENT_JITTER_MS_CONFIG = "segment.jitter.ms";
public static final String SEGMENT_JITTER_MS_DOC = "The maximum random jitter subtracted from the scheduled " +
"segment roll time to avoid thundering herds of segment rolling";
public static final String SEGMENT_INDEX_BYTES_CONFIG = "segment.index.bytes";
public static final String SEGMENT_INDEX_BYTES_DOC = "This configuration controls the size of the index that " +
"maps offsets to file positions. We preallocate this index file and shrink it only after log " +
"rolls. You generally should not need to change this setting.";
public static final String FLUSH_MESSAGES_INTERVAL_CONFIG = "flush.messages";
public static final String FLUSH_MESSAGES_INTERVAL_DOC = "This setting allows specifying an interval at " +
"which we will force an fsync of data written to the log. For example if this was set to 1 " +
"we would fsync after every message; if it were 5 we would fsync after every five messages. " +
"In general we recommend you not set this and use replication for durability and allow the " +
"operating system's background flush capabilities as it is more efficient. This setting can " +
"be overridden on a per-topic basis (see the per-topic configuration section).";
public static final String FLUSH_MS_CONFIG = "flush.ms";
public static final String FLUSH_MS_DOC = "This setting allows specifying a time interval at which we will " +
"force an fsync of data written to the log. For example if this was set to 1000 " +
"we would fsync after 1000 ms had passed. In general we recommend you not set " +
"this and use replication for durability and allow the operating system's background " +
"flush capabilities as it is more efficient.";
public static final String RETENTION_BYTES_CONFIG = "retention.bytes";
public static final String RETENTION_BYTES_DOC = "This configuration controls the maximum size a partition " +
"(which consists of log segments) can grow to before we will discard old log segments to free up space if we " +
"are using the \"delete\" retention policy. By default there is no size limit only a time limit. " +
"Since this limit is enforced at the partition level, multiply it by the number of partitions to compute " +
"the topic retention in bytes.";
public static final String RETENTION_MS_CONFIG = "retention.ms";
public static final String RETENTION_MS_DOC = "This configuration controls the maximum time we will retain a " +
"log before we will discard old log segments to free up space if we are using the " +
"\"delete\" retention policy. This represents an SLA on how soon consumers must read " +
"their data. If set to -1, no time limit is applied.";
public static final String MAX_MESSAGE_BYTES_CONFIG = "max.message.bytes";
public static final String MAX_MESSAGE_BYTES_DOC =
"The largest record batch size allowed by Kafka (after compression if compression is enabled). " +
"If this is increased and there are consumers older than 0.10.2, the consumers' fetch " +
"size must also be increased so that they can fetch record batches this large. " +
"In the latest message format version, records are always grouped into batches for efficiency. " +
"In previous message format versions, uncompressed records are not grouped into batches and this " +
"limit only applies to a single record in that case.";
public static final String INDEX_INTERVAL_BYTES_CONFIG = "index.interval.bytes";
public static final String INDEX_INTERVAL_BYTES_DOCS = "This setting controls how frequently " +
"Kafka adds an index entry to its offset index. The default setting ensures that we index a " +
"message roughly every 4096 bytes. More indexing allows reads to jump closer to the exact " +
"position in the log but makes the index larger. You probably don't need to change this.";
public static final String FILE_DELETE_DELAY_MS_CONFIG = "file.delete.delay.ms";
public static final String FILE_DELETE_DELAY_MS_DOC = "The time to wait before deleting a file from the " +
"filesystem";
public static final String DELETE_RETENTION_MS_CONFIG = "delete.retention.ms";
public static final String DELETE_RETENTION_MS_DOC = "The amount of time to retain delete tombstone markers " +
"for log compacted topics. This setting also gives a bound " +
"on the time in which a consumer must complete a read if they begin from offset 0 " +
"to ensure that they get a valid snapshot of the final stage (otherwise delete " +
"tombstones may be collected before they complete their scan).";
public static final String MIN_COMPACTION_LAG_MS_CONFIG = "min.compaction.lag.ms";
public static final String MIN_COMPACTION_LAG_MS_DOC = "The minimum time a message will remain " +
"uncompacted in the log. Only applicable for logs that are being compacted.";
public static final String MAX_COMPACTION_LAG_MS_CONFIG = "max.compaction.lag.ms";
public static final String MAX_COMPACTION_LAG_MS_DOC = "The maximum time a message will remain " +
"ineligible for compaction in the log. Only applicable for logs that are being compacted.";
public static final String MIN_CLEANABLE_DIRTY_RATIO_CONFIG = "min.cleanable.dirty.ratio";
public static final String MIN_CLEANABLE_DIRTY_RATIO_DOC = "This configuration controls how frequently " +
"the log compactor will attempt to clean the log (assuming log " +
"compaction is enabled). By default we will avoid cleaning a log where more than " +
"50% of the log has been compacted. This ratio bounds the maximum space wasted in " +
"the log by duplicates (at 50% at most 50% of the log could be duplicates). A " +
"higher ratio will mean fewer, more efficient cleanings but will mean more wasted " +
"space in the log. If the " + MAX_COMPACTION_LAG_MS_CONFIG + " or the " + MIN_COMPACTION_LAG_MS_CONFIG +
" configurations are also specified, then the log compactor considers the log to be eligible for compaction " +
"as soon as either: (i) the dirty ratio threshold has been met and the log has had dirty (uncompacted) " +
"records for at least the " + MIN_COMPACTION_LAG_MS_CONFIG + " duration, or (ii) if the log has had " +
"dirty (uncompacted) records for at most the " + MAX_COMPACTION_LAG_MS_CONFIG + " period.";
public static final String CLEANUP_POLICY_CONFIG = "cleanup.policy";
public static final String CLEANUP_POLICY_COMPACT = "compact";
public static final String CLEANUP_POLICY_DELETE = "delete";
public static final String CLEANUP_POLICY_DOC = "A string that is either \"" + CLEANUP_POLICY_DELETE +
"\" or \"" + CLEANUP_POLICY_COMPACT + "\" or both. This string designates the retention policy to use on " +
"old log segments. The default policy (\"delete\") will discard old segments when their retention " +
"time or size limit has been reached. The \"compact\" setting will enable log " +
"compaction on the topic.";
public static final String UNCLEAN_LEADER_ELECTION_ENABLE_CONFIG = "unclean.leader.election.enable";
public static final String UNCLEAN_LEADER_ELECTION_ENABLE_DOC = "Indicates whether to enable replicas " +
"not in the ISR set to be elected as leader as a last resort, even though doing so may result in data " +
"loss.";
public static final String MIN_IN_SYNC_REPLICAS_CONFIG = "min.insync.replicas";
public static final String MIN_IN_SYNC_REPLICAS_DOC = "When a producer sets acks to \"all\" (or \"-1\"), " +
"this configuration specifies the minimum number of replicas that must acknowledge " +
"a write for the write to be considered successful. If this minimum cannot be met, " +
"then the producer will raise an exception (either NotEnoughReplicas or " +
"NotEnoughReplicasAfterAppend).
When used together, min.insync.replicas and acks " +
"allow you to enforce greater durability guarantees. A typical scenario would be to " +
"create a topic with a replication factor of 3, set min.insync.replicas to 2, and " +
"produce with acks of \"all\". This will ensure that the producer raises an exception " +
"if a majority of replicas do not receive a write.";
public static final String COMPRESSION_TYPE_CONFIG = "compression.type";
public static final String COMPRESSION_TYPE_DOC = "Specify the final compression type for a given topic. " +
"This configuration accepts the standard compression codecs ('gzip', 'snappy', 'lz4', 'zstd'). It additionally " +
"accepts 'uncompressed' which is equivalent to no compression; and 'producer' which means retain the " +
"original compression codec set by the producer.";
public static final String PREALLOCATE_CONFIG = "preallocate";
public static final String PREALLOCATE_DOC = "True if we should preallocate the file on disk when " +
"creating a new log segment.";
public static final String MESSAGE_FORMAT_VERSION_CONFIG = "message.format.version";
public static final String MESSAGE_FORMAT_VERSION_DOC = "Specify the message format version the broker " +
"will use to append messages to the logs. The value should be a valid ApiVersion. Some examples are: " +
"0.8.2, 0.9.0.0, 0.10.0, check ApiVersion for more details. By setting a particular message format " +
"version, the user is certifying that all the existing messages on disk are smaller or equal than the " +
"specified version. Setting this value incorrectly will cause consumers with older versions to break as " +
"they will receive messages with a format that they don't understand.";
public static final String MESSAGE_TIMESTAMP_TYPE_CONFIG = "message.timestamp.type";
public static final String MESSAGE_TIMESTAMP_TYPE_DOC = "Define whether the timestamp in the message is " +
"message create time or log append time. The value should be either `CreateTime` or `LogAppendTime`";
public static final String MESSAGE_TIMESTAMP_DIFFERENCE_MAX_MS_CONFIG = "message.timestamp.difference.max.ms";
public static final String MESSAGE_TIMESTAMP_DIFFERENCE_MAX_MS_DOC = "The maximum difference allowed between " +
"the timestamp when a broker receives a message and the timestamp specified in the message. If " +
"message.timestamp.type=CreateTime, a message will be rejected if the difference in timestamp " +
"exceeds this threshold. This configuration is ignored if message.timestamp.type=LogAppendTime.";
public static final String MESSAGE_DOWNCONVERSION_ENABLE_CONFIG = "message.downconversion.enable";
public static final String MESSAGE_DOWNCONVERSION_ENABLE_DOC = "This configuration controls whether " +
"down-conversion of message formats is enabled to satisfy consume requests. When set to false, " +
"broker will not perform down-conversion for consumers expecting an older message format. The broker responds " +
"with UNSUPPORTED_VERSION error for consume requests from such older clients. This configuration" +
"does not apply to any message format conversion that might be required for replication to followers.";
}