Client Settings
- reference
The ClusterEnvironment
class enables you to configure Java SDK options for security, timeouts, reliability, and performance.
The Environment Builder
Most client settings are related to the ClusterEnvironment
.
Because ClusterEnvironment
is an immutable class, you need to configure it by using its embedded Builder
class.
It is designed to apply the builder arguments in a fluent fashion and then create the ClusterEnvironment
at the very end.
ClusterEnvironment env = ClusterEnvironment.builder()
// [Customize client settings here]
.build();
// Create a cluster using the custom client settings.
Cluster cluster = Cluster.connect(connectionString, ClusterOptions
.clusterOptions(username, password)
.environment(env));
// [Your code to interact with the cluster]
// Shut down gracefully.
cluster.disconnect();
env.shutdown();
Config Builders
Environment settings are grouped into categories, with one builder class per category. These builders all work in the same way, which we’ll illustrate by using timeout settings as an example.
Timeout settings are configured using an instance of TimeoutConfig.Builder
.
The usual way to create an instance is to call a static factory method on the TimeoutConfig
class.
The method TimeoutConfig.builder()
returns a builder with default settings.
There are also static factory methods that create a builder and set a configuration value in one step.
For example, instead of TimeoutConfig.builder().kvTimeout(…)
you can write simply TimeoutConfig.kvTimeout(…)
.
ClusterEnvironment env = ClusterEnvironment.builder()
.timeoutConfig(TimeoutConfig
.kvTimeout(Duration.ofSeconds(5))
.queryTimeout(Duration.ofSeconds(10)))
.build();
Another way to obtain an instance of a config builder is to borrow it from the cluster environment builder. This technique may be useful if you’re configuring the environment in stages and wish to preserve values set by a previous stage.
ClusterEnvironment.Builder envBuilder = ClusterEnvironment.builder();
envBuilder.timeoutConfig() // returns a TimeoutConfig.Builder
.kvTimeout(Duration.ofSeconds(5))
.queryTimeout(Duration.ofSeconds(10));
ClusterEnvironment env = envBuilder.build();
The name of the cluster environment builder method for getting and setting each config builder always matches the name of the config class.
For example, TimeoutConfig
is set via the environment builder’s timeoutConfig
method, IoConfig
is set via the ioConfig
method, and so on.
System Properties
Many client settings may also be configured by setting a Java system property. If a system property is set, it always takes precedence over the builder setting.
System.setProperty("com.couchbase.env.timeout.kvTimeout", "10s"); (1)
System.setProperty("com.couchbase.env.timeout.queryTimeout", "15s");
ClusterEnvironment environment = ClusterEnvironment.builder()
.timeoutConfig(TimeoutConfig.kvTimeout(Duration.ofSeconds(5))) (2)
.build();
1 | When specifying durations, s stands for seconds.
Other valid qualifiers are ns for nanoseconds, us for microseconds, ms for milliseconds, and m for minutes. |
2 | The kvTimeout value specified via TimeoutConfig.Builder is overridden by the system property.
In this example the actual kvTimeout is 10 seconds, and the queryTimeout is 15 seconds. |
System property names starting with com.couchbase.env are paths in a Java object graph rooted at the environment builder.
Setting the property com.couchbase.env.timeout.kvTimeout tells the SDK to invoke envBuilder.timeoutConfig().kvTimeout(…) using reflection.
|
Configuration Options
The following sections cover all possible configuration options and explain their usage and default values. They are categorized into groups for security, I/O, circuit breakers, timeout, compression, and general options.
Security Options
By default the client will connect to Couchbase Server using an unencrypted connection. If you are using the Enterprise Edition, it’s possible to secure the connection using TLS.
ClusterEnvironment env = ClusterEnvironment.builder()
.securityConfig(SecurityConfig
.enableTls(true)
)
.build();
Unless you set enableTls to true , none of the other security settings in this section have any effect.
|
- Name: Enabling Secure Connections
-
Builder Method:
SecurityConfig.enableTls(boolean)
Default:
false
System Property:
com.couchbase.env.security.enableTls
Set this to
true
to encrypt all communication between the client and server using TLS. This feature requires the Enterprise Edition of Couchbase Server 3.0 or later. If TLS is enabled you must also specify the trusted certificates by calling exactly one oftrustCertificate
,trustCertificates
, ortrustManagerFactory
. Please see the Managing Connections section for more details on how to set it up properly. - Name: Disabling Native TLS Provider
-
Builder Method:
SecurityConfig.enableNativeTls(boolean)
Default:
true
System Property:
com.couchbase.env.security.enableNativeTls
When TLS is enabled, the client will by default use an optimized native TLS provider if one is available. If for some reason you need to disable the native provider and use the JDK’s portable provider instead, set this to
false
. IfenableTls
isfalse
thenenableNativeTls
has no effect. - Name: TLS Certificate Location
-
Builder Method:
SecurityConfig.trustCertificate(Path)
Default: N/A
System Property:
com.couchbase.env.security.trustCertificate
Path to a file containing a single X.509 certificate to trust as a Certificate Authority when establishing secure connections. See the Connection Management section for more details on how to set it up properly.
- Name: TLS Certificates
-
Builder Method:
SecurityConfig.trustCertificates(List<X509Certificate>)
Default: N/A
System Property: N/A
If you wish to trust more than one certificate, or prefer to load the certificate yourself, then call this method to specify the certificates to trust as Certificate Authorities when establishing secure connections. See the Connection Management section for more details on how to set it up properly.
- Name: Custom TLS Trust Manager Factory
-
Builder Method:
SecurityConfig.trustManagerFactory(TrustManagerFactory)
Default: N/A
System Property: N/A
As an alternative to specifying the certificates to trust, you can specify a custom
TrustManagerFactory
to use when establishing secure connections. See the Connection Management section for more details on how to set it up properly.
I/O Options
I/O settings are represented by the Java class IoConfig
.
The associated ClusterEnvironment.Builder
method is called ioConfig
.
ClusterEnvironment env = ClusterEnvironment.builder()
.ioConfig(IoConfig
.networkResolution(NetworkResolution.AUTO)
)
.build();
- Name: DNS SRV Enabled
-
Builder Method:
IoConfig.enableDnsSrv(boolean)
Default:
true
System Property:
com.couchbase.env.io.enableDnsSrv
Gets the bootstrap node list from a DNS SRV record. See the Connection Management section for more information on how to use it properly.
- Name: Mutation Tokens Enabled
-
Builder Method:
IoConfig.mutationTokensEnabled(boolean)
Default:
true
System Property:
com.couchbase.env.io.mutationTokensEnabled
Mutation tokens allow enhanced durability requirements as well as advanced SQL++ (formerly N1QL) querying capabilities. Set this to
false
if you do not require these features and wish to avoid the associated overhead. - Name: Network Resolution
-
Builder Method:
IoConfig.networkResolution(NetworkResolution)
Default:
auto
System Property:
com.couchbase.env.io.networkResolution
The system property value should be one of auto
,default
, orexternal
(lower case).Each node in the Couchbase Server cluster might have multiple addresses associated with it. For example, a node might have one address that should be used when connecting from inside the same virtual network environment where the server is running, and a second address for connecting from outside the server’s network environment.
By default the client will use a simple matching heuristic to determine which set of addresses to use (it will select the set of addresses that contains a seed node’s host and port).
If you wish to override the heuristic, you can set this value to
default
if the client is running in the same network as the server, orexternal
if the client is running in a different network. - Name: Capture Traffic
-
Builder Method:
IoConfig.captureTraffic(ServiceType…)
Default: capture is disabled
System Property:
com.couchbase.env.io.captureTraffic
Multiple services may be specified in the system property value using a comma-delimited list such as KV,QUERY
. To enable capture for all services, set the value of the system property to an empty string.Call this method to log all traffic to the specified services. If no services are specified, traffic to all services is captured.
- Name: Socket Keepalive
-
Builder Method:
IoConfig.enableTcpKeepAlives(boolean)
Default:
true
System Property:
com.couchbase.env.io.enableTcpKeepAlives
If enabled, the client periodically sends a TCP keepalive to the server to prevent firewalls and other network equipment from dropping idle TCP connections.
- Name: Socket Keepalive Interval
-
Builder Method:
IoConfig.tcpKeepAliveTime(Duration)
Default:
60s
System Property:
com.couchbase.env.io.tcpKeepAliveTime
The idle time after which a TCP keepalive gets fired. (This setting has no effect if
enableTcpKeepAlives
isfalse
.)This setting only propagates to the OS on Linux when the epoll transport is used. On all other platforms, the OS-configured time is used (and you need to tune it there if you want to override the default interval). - Name: Key/Value Endpoints per Node
-
Builder Method:
IoConfig.numKvConnections(int)
Default:
1
System Property:
com.couchbase.env.io.numKvConnections
The number of actual endpoints (sockets) to open per node in the cluster against the Key/Value service. By default, for every node in the cluster one socket is opened where all traffic is pushed through. That way the SDK implicitly benefits from network batching characteristics when the workload increases. If you suspect based on profiling and benchmarking that the socket is saturated you can think about slightly increasing it to have more "parallel pipelines". This might be especially helpful if you need to push large documents through it. The recommendation is keeping it at 1 unless there is other evidence.
Durable Write operations with Couchbase Server 6.5 and above require up to 16 kvEndpoints per node, for most efficient operation, unless the environment dictates something a little lower. - Name: Max HTTP Endpoints per Service per Node
-
Builder Method:
IoConfig.maxHttpConnections(int)
Default:
12
System Property:
com.couchbase.env.io.maxHttpConnections
Each service (except the Key/Value service) has a separate dynamically sized pool of HTTP connections for issuing requests. This setting puts an upper bound on the number of HTTP connections in each pool.
- Name: Idle HTTP Connection Timeout
-
Builder Method:
IoConfig.idleHttpConnectionTimeout(Duration)
Default:
4.5s
System Property:
com.couchbase.env.io.idleHttpConnectionTimeout
The length of time an HTTP connection may remain idle before it is closed and removed from the pool. Durations longer than 50 seconds are not recommended, since some services have a 1 minute server side idle timeout.
- Name: Config Poll Interval
-
Builder Method:
IoConfig.configPollInterval(Duration)
Default:
2.5s
System Property:
com.couchbase.env.io.configPollInterval
The interval at which the client fetches cluster topology information in order to proactively detect changes.
Circuit Breaker Options
Circuit breakers are a tool for preventing cascading failures.
When a circuit is closed, requests are sent to the server as normal. If too many requests fail within a certain time window, the breaker opens the circuit, preventing requests from going through.
When a circuit is open, any requests to the service immediately fail without the client even talking to the server. After a "sleep delay" elapses, the next request is allowed to go through the to the server. This trial request is called a "canary."
Each service has an associated circuit breaker which may be configured independently of the others.
The IoConfig
builder has methods for configuring the circuit breakers of each service.
ClusterEnvironment env = ClusterEnvironment.builder()
.ioConfig(IoConfig.
kvCircuitBreakerConfig(CircuitBreakerConfig.builder()
.enabled(true)
.volumeThreshold(45)
.errorThresholdPercentage(25)
.sleepWindow(Duration.ofSeconds(1))
.rollingWindow(Duration.ofMinutes(2))
))
.build();
The corresponding system properties would be:
com.couchbase.env.io.kvCircuitBreaker.enabled=true
com.couchbase.env.io.kvCircuitBreaker.volumeThreshold=45
com.couchbase.env.io.kvCircuitBreaker.errorThresholdPercentage=25
com.couchbase.env.io.kvCircuitBreaker.sleepWindow=1s
com.couchbase.env.io.kvCircuitBreaker.rollingWindow=2m
For the other services, replace kv
with query
, view
, search
, analytics
, or manager
.
The properties of a circuit breaker are described below.
- enabled
-
Default:
true
Enables or disables this circuit breaker.
If this property is set to false, then the circuit breaker is not used and all other properties are ignored.
- volumeThreshold
-
Default:
20
The volume threshold defines how many operations must be in the window before the threshold percentage can be meaningfully calculated.
- errorThresholdPercentage
-
Default:
50
The percentage of operations in a window that may fail before the circuit is opened. The value is an integer in the range [0,100].
- sleepWindow
-
Default:
5s
The delay between when the circuit opens and when the canary is tried.
- rollingWindow
-
Default:
1m
How long the window is in which the number of failed ops are tracked in a rolling fashion.
Timeout Options
The default timeout values are suitable for most environments, and should be adjusted only after profiling the expected latencies in your deployment environment. If you get a timeout exception, it may be a symptom of another issue; increasing the timeout duration is sometimes not the best long-term solution.
Most timeouts can be overridden on a per-operation basis (for example, by passing a custom options block to a "get" or "query" method). The values set here are used as the defaults when no per-operation timeout is specified. See setting duration values under System Properties.
Timeout settings are represented by the Java class TimeoutConfig
.
The associated ClusterEnvironment.Builder
method is called timeoutConfig
.
ClusterEnvironment env = ClusterEnvironment.builder()
.timeoutConfig(TimeoutConfig
.kvTimeout(Duration.ofMillis(2500))
)
.build();
- Name: Key-Value Timeout
-
Builder Method:
TimeoutConfig.kvTimeout(Duration)
Default:
2.5s
— but see TIP, belowSystem Property:
com.couchbase.env.timeout.kvTimeout
The Key/Value default timeout is used on operations which are performed on a specific key if not overridden by a custom timeout. This includes all commands like get(), getFromReplica() and all mutation commands, but does not include operations that are performed with enhanced durability requirements.
Durable Write operations have their own timeout setting, kvDurableTimeout
, see below. - Name: Key-Value Durable Operation Timeout
-
Builder Method:
TimeoutConfig.kvDurableTimeout(Duration)
Default:
10s
System Property:
com.couchbase.env.timeout.kvDurableTimeout
Key/Value operations with enhanced durability requirements may take longer to complete, so they have a separate default timeout.
Do not set this above 65s, which is the maximum possible
SyncWrite
timeout on the Server side.The kvDurableTimeout
property is not part of the stable API and may change or be removed at any time.
- Name: View Timeout
-
Builder Method:
TimeoutConfig.viewTimeout(Duration)
Default:
75s
System Property:
com.couchbase.env.timeout.viewTimeout
The View timeout is used on view operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows. Also, if there is a node failure during the request the internal cluster timeout is set to 60 seconds.
- Name: Query Timeout
-
Builder Method:
TimeoutConfig.queryTimeout(Duration)
Default:
75s
System Property:
com.couchbase.env.timeout.queryTimeout
The Query timeout is used on all SQL++ query operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.
- Name: Search Timeout
-
Builder Method:
TimeoutConfig.searchTimeout(Duration)
Default:
75s
System Property:
com.couchbase.env.timeout.searchTimeout
The Search timeout is used on all FTS operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.
- Name: Analytics Timeout
-
Builder Method:
TimeoutConfig.analyticsTimeout(Duration)
Default:
75s
System Property:
com.couchbase.env.timeout.analyticsTimeout
The Analytics timeout is used on all Analytics query operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.
- Name: Connect Timeout
-
Builder Method:
TimeoutConfig.connectTimeout(Duration)
Default:
10s
System Property:
com.couchbase.env.timeout.connectTimeout
The connect timeout is used when a Bucket is opened and if not overridden by a custom timeout. If you feel the urge to change this value to something higher, there is a good chance that your network is not properly set up. Connecting to the server should in practice not take longer than a second on a reasonably fast network.
- Name: Disconnect Timeout
-
Builder Method:
TimeoutConfig.disconnectTimeout(Duration)
Default:
10s
System Property:
com.couchbase.env.timeout.disconnectTimeout
The disconnect timeout is used when a Cluster is disconnected and if not overridden by a custom timeout. A timeout is applied here always to make sure that your code does not get stuck at shutdown. The default should provide enough time to drain all outstanding operations properly, but make sure to adapt this timeout to fit your application requirements.
- Name: Management Timeout
-
Builder Method:
TimeoutConfig.managementTimeout(Duration)
Default:
75s
System Property:
com.couchbase.env.timeout.managementTimeout
The management timeout is used on all cluster management APIs (BucketManager, UserManager, CollectionManager, QueryIndexManager, etc.) if not overridden by a custom timeout. The default is quite high because some operations (such as flushing a bucket, for example) might take a long time.
Compression Options
The client can optionally compress documents before sending them to Couchbase Server.
Compression settings are represented by the Java class CompressionConfig
.
The associated ClusterEnvironment.Builder
method is called compressionConfig
.
ClusterEnvironment env = ClusterEnvironment.builder()
.compressionConfig(CompressionConfig.create().enable(true))
.build();
- Name: Enabling Compression
-
Builder Method:
CompressionConfig.enabled
Default:
true
System Property:
com.couchbase.env.compression.enable(boolean)
If enabled, the client will compress documents before they are sent to Couchbase Server. If this is set to
false
, the other CompressionExample settings have no effect. - Name: Document Minimum Size
-
Builder Method:
CompressionConfig.minSize(int)
Default:
32
System Property:
com.couchbase.env.compression.minSize
Size in bytes. Documents smaller than this size are never compressed.
- Name: Document Minimum Compressibility
-
Builder Method:
CompressionConfig.minRatio(double)
Default:
0.83
System Property:
com.couchbase.env.compression.minRatio
A floating point value between 0 and 1. Specifies how "compressible" a document must be in order for the compressed form to be sent to the server.
Increasing the value allows CompressionExample to be used with less-compressible documents. If the compressed document size divided by the uncompressed document size is greater than this value, then the uncompressed version of the document will be sent to Couchbase Server instead of the compressed version.
For example, with a
minRatio
of0.83
, CompressionExample will only be used if the size of the compressed document is less than 83% of the uncompressed document size.
General Options
The settings in this category apply to the client in general.
They are configured directly on the ClusterEnvironment.Builder
.
ClusterEnvironment env = ClusterEnvironment.builder()
.retryStrategy(BestEffortRetryStrategy.INSTANCE)
.build();
- Name: Retry Strategy
-
Builder Method:
retryStrategy(RetryStrategy)
Default:
BestEffortRetryStrategy.INSTANCE
System Property: N/A
The client’s default retry strategy.
A retry strategy decides whether a failed operation should be retried. Implementing a custom strategy is fairly advanced, so the SDK ships with two out of the box:
BestEffortRetryStrategy
andFailFastRetryStrategy
.The "best effort" strategy will retry the operation until it either succeeds or the timeout expires. The "fail fast" strategy will immediately report the failure to your application, giving you more control over how and when to retry.
Most client operations that accept an options block allow for overriding the default strategy as one of the options. See the advanced section in the documentation on more specific information on retry strategies and failure management.
- Name: Unordered Execution
-
Builder Method:
unorderedExecutionEnabled(boolean)
Default:
true
System Property:
com.couchbase.unorderedExecutionEnabled
From Couchbase 7.0, Out-of-Order execution allows the server to concurrently handle multiple requests on the same connection, potentially improving performance for durable writes and multi-document ACID transactions. This means that tuning the number of connections (KV endpoints) is no longer necessary as a workaround where data not available in the cache is causing timeouts.
This is set to
true
by default. Note, changing the setting will only affect Server versions 7.0 onwards. - Name: JSON Serializer
-
Builder Method:
jsonSerializer(JsonSerializer)
Default: see below
System Property: N/A
The JSON serializer handles the conversion between JSON and Java objects.
If Jackson is present in the class path, the default serializer will be an instance of
JacksonJsonSerializer
using a defaultObjectMapper
.To create a serializer backed by a custom ObjectMapper
, callJacksonJsonSerializer.create
and pass in your custom mapper.If Jackson is not present, the client will fall back to using an unspecified default serializer. (Actually, it will use a repackaged version of Jackson, but this is an implementation detail you should not depend on.)
- Name: Transcoder
-
Builder Method:
transcoder(Transcoder)
Default:
JsonTranscoder
System Property: N/A
The transcoder is responsible for converting KV binary packages to and from Java objects.
The default transcoder assumes you are working with JSON documents. It uses the configured
jsonSerializer
to convert between JSON and Java objects. When writing documents it sets the appropriate flags to indicate the document content is JSON.The transcoder configured here is just the default; it can be overridden on a per-operation basis.
- Name: Request Tracer
-
Builder Method:
requestTracer(RequestTracer)
Default:
ThresholdRequestTracer
System Property: N/A
The default tracer logs the slowest requests per service.
Various
RequestTracer
implementations exist, both as part of the core library and as external modules that can be attached (i.e. for OpenTracing and OpenTelemetry). It is recommended to use those modules and not write your own tracer unless absolutely needed.When using a non-default tracer, you are responsible for starting and stopping it. - Name: Computation Scheduler
-
Builder Method:
scheduler(Scheduler)
Default: see below
System Property: N/A
This is an advanced setting that should not be modified without good reason.
The scheduler used for all CPU-intensive, non-blocking computations in the core, client, and user space. The default is a scheduler created from Reactor’s
Schedulers.newParallel
method, with one daemon thread per CPU core. Extra care should be used when changing the scheduler, since many internal components depend on it.Shutting down the cluster environment will not dispose of a custom scheduler. You are responsible for disposing of it after it is no longer needed. - Name: Event Bus
-
Builder Method:
eventBus(EventBus)
Default:
DefaultEventBus
System Property: N/A
This is an advanced setting that should not be modified without good reason.
The event bus implementation used to transport system, performance, and debug events from producers to subscribers. If you provide a custom implementation, double check that it fits with the contract of the event bus as documented.
Shutting down the cluster environment will not stop a custom event bus. You are responsible for stopping it after it is no longer needed.
Commonly Used Options
The defaults above have been carefully considered and in general it is not recommended to make changes without expert guidance or careful testing of the change. Some options may be commonly used together in certain envionments or to achieve certain effects.
Constrained Network Environments
Though wide area network (WAN) connections are not directly supported, some development and non-critical operations activities across a WAN are convenient. Most likely for connecting to Couchbase Capella, or Server running in your own cloud account, whilst developing from a laptop or other machine not located in the same data center. These settings are some you may want to consider adjusting:
-
Connect Timeout to 30s
-
Key-Value Timeout to 5s
-
Config Poll Interval to 10s
-
Circuit Breaker ErrorThresholdPercentage to 75
As of SDK API 3.4 you can also use a Configuration Profile, which allows you to quickly configure your environment for common use-cases. See the Configuration Profiles section for more details. |
A program using the SDK can also use the waitUntilReady()
API call to handle all connection negotiations and related errors at one place.
It may be useful to block in, for example, a basic console testing application for up to 30 seconds before proceeding in the program to perform data operations.
See the API reference for further details.
Configuration Profiles
Configuration Profiles provide predefined client settings that allow you to quickly configure an environment for common use-cases. When using a configuration profile, the current client settings are overridden with the values provided in the profile. Any property that is not specified in the profile is left unchanged.
The Configuration Profiles feature is currently a Volatile API and may be subject to change. |
WAN Development
Builder Method: applyProfile("wan-development")
A wan-development
configuration profile can be used to modify client settings for development or high-latency environments.
This profile changes the default timeouts.
Setting | Value |
---|---|
|
20s |
|
20s |
|
20s |
|
120s |
|
120s |
|
120s |
|
120s |
|
120s |