Setting List

Detailed Description

Adjust tunables for the client

The constants in this file are used to control the behavior of the library. All of the operations above may be passed as the cmd parameter to the lcb_cntl() function, thus:

char something;
lcb_STATUS rv;
rv = lcb_cntl(instance, LCB_CNTL_GET, LCB_CNTL_FOO, &something);

will retrieve the setting of LCB_CNTL_FOO into something.

You may also use the lcb_cntl_string() function, which operates on strings and can set various configuration properties fairly simply. Note however that string names are subject to change, and not all configuration directives have a string alias:

rv = lcb_cntl_string("operation_timeout", "5.0");

Of the commands listed below, some will be read-only (i.e. you may only read the setting using the LCB_CNTL_GET mode), some will be write-only (i.e. you may only modify the setting, and use LCB_CNTL_SET for the mode) and some will be both readable and writable.

Along the documentation of each specific command, there is a table displaying the modes supported and the expected pointer type to be passed as the arg value into lcb_cntl(). Note that some read-write commands require different pointer types depending on whether the mode is retrieval or storage.

Timeout and Time Value Settings

There are various settings on the library that control behavior with respect to wall clock time.

Timeout settings control how long the library will wait for a certain event before proceeding to the next course of action (which may either be to try a different operation or fail the current one, depending on the specific timeout).

Other settings may configure how often the library proactively polls for a configuration update, retries various interally retried operations and so forth.

Time values are specified in microseconds stored within an lcb_U32.

When specified as an argument to lcb_cntl_string() or through the connection string, it will be parsed from a string float value where the integer-part is in seconds and the fractional-part is in fractions of a second.

Note that timeouts in libcouchbase are implemented via an event loop scheduler. As such their accuracy and promptness is limited by how often the event loop is invoked and how much wall time is spent in each of their handlers. Specifically if you issue long running blocking calls within any of the handlers (and this means any of the library's callbacks) then the timeout accuracy will be impacted.

Further behavior is dependent on the event loop plugin itself and how it schedules timeouts.

Configuration Stability Attributes

Configuration parameters are still subject to the API classification used in Interface Attributes. For deprecated control commands, lcb_cntl() will either perform the operation, or consider it a no-op, or return an error code.

Stability

Internal

Modes
Modes for the lcb_cntl() mode argument
#define	LCB_CNTL_SET
	Modify a setting.
#define	LCB_CNTL_GET
	Retrieve a setting.

Logging
Verbose logging may be enabled by default using the environment variable LCB_LOGLEVEL and setting it to a number > 1; higher values produce more verbose output. The maximum level is 5. You may also install your own logger using lcb_cntl() and the LCB_CNTL_LOGGER constant. Note that the logger functions will not be called rapidly from within hot paths.
#define	LCB_CNTL_LOGGER
	Access the lcb_LOGGER structure.

---

Data Structure Documentation

lcb_cntl_server_t

struct lcb_cntl_server_t

Information describing the server.

Stability

Internal

Data Fields
int	version	Structure version.
union lcb_cntl_server_t.v	v

lcb_cntl_iops_info_st

struct lcb_cntl_iops_info_st

Information about the I/O plugin.

Stability

Internal

Data Fields
int	version
union lcb_cntl_iops_info_st.v	v

lcb_cntl_rdballocfactory

struct lcb_cntl_rdballocfactory

Structure being used because function pointers can't technically be cast to void*.

Data Fields
lcb_RDBALLOCFACTORY	factory

lcb_cntl_vbinfo_t

struct lcb_cntl_vbinfo_t

Structure containing mapping information for a key.

Data Fields
int	version
union lcb_cntl_vbinfo_t.v	v

lcb_cntl_server_t.v.v1

struct lcb_cntl_server_t.v.v1

Current information here.

Data Fields
LCB_CNTL_SERVER_COMMON_FIELDS const char *	sasl_mech	Chosen SASL mechanism.

lcb_cntl_vbinfo_t.v.v0

struct lcb_cntl_vbinfo_t.v.v0

v0

Data Fields
const void *	key	Input Key
lcb_SIZE	nkey	Input Length of key
int	vbucket	Output Mapped vBucket
int	server_index	Output Server index for vBucket

Macro Definition Documentation

LCB_CNTL_SERVER_COMMON_FIELDS

#define LCB_CNTL_SERVER_COMMON_FIELDS

Stability

Internal

LCB_CNTL_MEMDNODE_INFO

#define LCB_CNTL_MEMDNODE_INFO

Get information about a memcached node.

Stability

Internal

This function will populate a structure containing various information about the specific host

Note that all fields in the structure are only valid until the following happens (whichever is first)

1. Another libcouchbase API function is called
2. The event loop regains control

Argument

Modes	Arg
Get	lcb_cntl_server_t*

Stability

Volatile

LCB_CNTL_CONFIGNODE_INFO

#define LCB_CNTL_CONFIGNODE_INFO

Get information about the configuration node.

Stability

Internal

Note that this may not be available if the configuration mode is not HTTP

Argument

Modes	Arg
Get	lcb_cntl_server_t*

Stability

Volatile

LCB_CNTL_IOPS_DEFAULT_TYPES

#define LCB_CNTL_IOPS_DEFAULT_TYPES

Get the default IOPS types for this build.

Stability

Internal

This provides a convenient way to determine what libcouchbase will use for IO when not explicitly specifying an iops structure to lcb_create()

Argument

Modes	Arg
Get	lcb_cntl_io_ops_info_st*

Note

You may pass NULL to lcb_cntl for the 'instance' parameter, as this does not read anything specific on the handle

Stability

Uncommitted

LCB_CNTL_CONFIG_HTTP_NODES

#define LCB_CNTL_CONFIG_HTTP_NODES

Set the nodes for the HTTP provider.

Stability

Internal

Stability

Uncommitted

This sets the initial list for the nodes to be used for bootstrapping the cluster. This may also be used subsequently in runtime to provide an updated list of nodes if the current list malfunctions.

The argument for this cntl accepts a NUL-terminated string containing one or more nodes. The format for this string is the same as the host parameter in lcb_create_st

Ports should specify the REST API port.

Argument

Modes	Arg
Set	char** (Array of strings)

LCB_CNTL_CONFIG_CCCP_NODES

#define LCB_CNTL_CONFIG_CCCP_NODES

Set the nodes for the CCCP provider.

Stability

Internal

Similar to LCB_CNTL_CONFIG_HTTP_NODES, but affects the CCCP provider instead. Ports should specify the memcached port

Argument

Modes	Arg
Set	char** (Array of strings)

Stability

Uncommitted

LCB_CNTL_REINIT_CONNSTR

#define LCB_CNTL_REINIT_CONNSTR

Reinitialize the instance using a connection string.

Only options and the hostlists are used from this string. The bucket in the string (if specified) and any SSL options (i.e. couchbases:// or ssl=no_verify) are ignored.

This is the newer variant of LCB_CNTL_CONFIG_ALL_NODES

Argument

Modes	Arg
Set	const char *

Stability

Internal

LCB_CNTL_RDBALLOCFACTORY

#define LCB_CNTL_RDBALLOCFACTORY

Set the allocator factory used by libcouchbase.

The allocator factory is a function invoked with no arguments which yields a new rdb_ALLOCATOR object. Currently the use and API of this object is considered internal and its API and header files are in src/rdb.

Mode	Arg
Set, Get	lcb_cntl_rdballocfactory*

Stability

Volatile

LCB_CNTL_VBGUESS_PERSIST

#define LCB_CNTL_VBGUESS_PERSIST

Persist heuristic vbucket information across updates.

As of version 2.4.8 this option no longer has any effect, and vBucket heuristics are always retained for a maximum of 20 seconds.

Argument

Modes	Arg
Get, Set	int*

Stability

Volatile

LCB_CNTL_UNSAFE_OPTIMIZE

#define LCB_CNTL_UNSAFE_OPTIMIZE

This is a collection of various options which sacrifice data safety for speed.

Stability

Volatile

LCB_CNTL_TCP_NODELAY

#define LCB_CNTL_TCP_NODELAY

Disable or enable Nagle's algorithm.

The default is to disable it, as it will typically reduce latency. In general it is recommended not to touch this setting. It is here mainly for debugging.

Conventionally, the option to disable Nagle's algorithm is called "TCP_NODELAY", thus if this value is one, Nagle is off, and vice versa.

Stability

Volatile

LCB_CNTL_KVTIMINGS

#define LCB_CNTL_KVTIMINGS

Get the lcb_HISTOGRAM object for key-value timings.

Argument

Modes	Arg
Get	lcb_HISTOGRAM**

Stability

Volatile

LCB_CNTL_METRICS

#define LCB_CNTL_METRICS

Stability

Volatile

Activate/Get library metrics per-server

If using LCB_CNTL_SET, then this will activate the metrics, and should be called immediately after lcb_create. The arg parameter should be a pointer to an integer with the activation value (any non-zero value to activate).

If using LCB_CNTL_GET, the arg parameter should be a `lcb_METRICS**` variable, which will contain the pointer to the metrics upon completion.

LCB_CNTL_VB_NOREMAP

#define LCB_CNTL_VB_NOREMAP

Do not use fast-forward map from cluster configuration.

Use vb_noremap in the connection string

Argument

Modes	Arg
Get, Set	int* (as boolean)

Stability

Uncommitted

LCB_CNTL_WAIT_FOR_CONFIG

#define LCB_CNTL_WAIT_FOR_CONFIG

Do not wait for GET_CLUSTER_CONFIG request to finish in lcb_wait(), when it is the only request in retry queue.

Consider such retry queue as empty, and breakout to the place where lcb_wait() was invoked.

Argument

Modes	Arg
Get, Set	int* (as boolean)

Stability

Uncommitted

LCB_CNTL_QUERY_GRACE_PERIOD

#define LCB_CNTL_QUERY_GRACE_PERIOD

N1QL grace period This is time interval that will be added to I/O timeout of N1QL queries to amortize time spent on LCB time during request handing.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_OP_TIMEOUT

#define LCB_CNTL_OP_TIMEOUT

Operation Timeout.

The operation timeout is the maximum amount of time the library will wait for an operation to receive a response before invoking its callback with a failure status.

An operation may timeout if:

• A server is taking too long to respond
• An updated cluster configuration has not been promptly received

lcb_U32 tmo = 3500000;
lcb_cntl(instance, LCB_CNTL_SET, LCB_CNTL_OP_TIMEOUT, &tmo);

Argument

Modes	Arg
Get, Set	lcbU32*

Stability

Committed

See also

lcb-time-info

LCB_CNTL_VIEW_TIMEOUT

#define LCB_CNTL_VIEW_TIMEOUT

Views Timeout This is the I/O timeout for HTTP requests issues with LCB_HTTP_TYPE_VIEWS.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_QUERY_TIMEOUT

#define LCB_CNTL_QUERY_TIMEOUT

N1QL Timeout This is the I/O timeout for N1QL queries, issued via lcb_n1ql_query()

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_BUCKETNAME

#define LCB_CNTL_BUCKETNAME

Get the name of the bucket This returns the name of the bucket this instance is connected to, or NULL if not yet connected to a bucket.

Argument

Modes	Arg
Get	const char*

Stability

Committed

Examples

example/analytics/analytics.c, example/fts/fts.c, and example/minimal/query.c.

LCB_CNTL_BUCKETTYPE

#define LCB_CNTL_BUCKETTYPE

Get the bucket type.

This returns the bucket type - which is either of the following:

• LCB_BTYPE_UNSPEC
• LCB_BTYPE_COUCHBASE
• LCB_BTYPE_EPHEMERAL
• LCB_BTYPE_MEMCACHED

See also

https://developer.couchbase.com/documentation/server/current/architecture/core-data-access-buckets.html

Argument

Modes	Arg
Get	lcb_BTYPE*

LCB_CNTL_HANDLETYPE

#define LCB_CNTL_HANDLETYPE

Get the handle type.

This returns the handle type - which is either LCB_TYPE_CLUSTER or LCB_TYPE_BUCKET

Argument

Modes	Arg
Get	lcb_type_t*

LCB_CNTL_VBCONFIG

#define LCB_CNTL_VBCONFIG

Get the vBucket handle.

Obtains the current cluster configuration from the client.

Argument

Modes	Arg
Get	lcbvb_CONFIG**

LCB_CNTL_IOPS

#define LCB_CNTL_IOPS

Get the iops implementation instance.

Argument

Modes	Arg
Get	lcb_io_opt_t*

Stability

Uncommitted

LCB_CNTL_VBMAP

#define LCB_CNTL_VBMAP

Get the vBucket ID for a given key, based on the current configuration.

Argument

Modes	Arg
Get	lcb_cntl_vbinfo_t*

Stability

Committed

LCB_CNTL_IP6POLICY

#define LCB_CNTL_IP6POLICY

IPv4/IPv6 selection policy.

Setting which controls whether hostname lookups should prefer IPv4 or IPv6

Use ipv6 in the connection string (e.g. "ipv6=allow" or "ipv6=only")

Argument

Modes	Arg
Get, Set	lcb_ipv6_t*

Stability

Committed

LCB_CNTL_CONFERRTHRESH

#define LCB_CNTL_CONFERRTHRESH

Configuration error threshold.

This number indicates how many network/mapping/not-my-vbucket errors are received before a configuration update is requested again.

Argument

Modes	Arg
Get, Set	lcb_SIZE*

LCB_CNTL_DURABILITY_TIMEOUT

#define LCB_CNTL_DURABILITY_TIMEOUT

Default timeout for lcb_durability_poll()

This is the time the client will spend sending repeated probes to a given key's vBucket masters and replicas before they are deemed not to have satisfied the durability requirements

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_DURABILITY_INTERVAL

#define LCB_CNTL_DURABILITY_INTERVAL

Polling grace interval for lcb_durability_poll()

This is the time the client will wait between repeated probes to a given server.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_HTTP_TIMEOUT

#define LCB_CNTL_HTTP_TIMEOUT

Timeout for otherwise unspecified HTTP requests.

Examples of these kinds of HTTP requests might be cluster management, user management, etc.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_IOPS_DLOPEN_DEBUG

#define LCB_CNTL_IOPS_DLOPEN_DEBUG

Print verbose plugin load information to console.

This modifies a static, global setting regarding whether to print verbose information when trying to dynamically load an IO plugin. The information printed can be useful in determining why a plugin failed to load. This setting can also be controlled via the "LIBCOUCHBASE_DLOPEN_DEBUG" environment variable (and if enabled from the environment, will override the setting mentioned here).

Argument

Modes	Arg
Get, Set	int*

Note

Pass NULL to lcb_cntl for the 'instance' parameter.

Stability

Volatile

LCB_CNTL_CONFIGURATION_TIMEOUT

#define LCB_CNTL_CONFIGURATION_TIMEOUT

Initial bootstrap timeout.

This is how long the client will wait to obtain the initial configuration.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_RANDOMIZE_BOOTSTRAP_HOSTS

#define LCB_CNTL_RANDOMIZE_BOOTSTRAP_HOSTS

Randomize order of bootstrap nodes.

This controls whether the connection attempts for configuration retrievals should be done in the supplied order or whether they should be randomized.

For the initial connection the supplied order is the list of hosts provided in the lcb_create_st structure. For subsequent connections this is the order of nodes as received by the server.

Argument

Modes	Arg
Get, Set	int*

Stability

Committed

LCB_CNTL_CONFIG_CACHE_LOADED

#define LCB_CNTL_CONFIG_CACHE_LOADED

Determine if file-based configuration has been loaded.

If the configuration cache is in use, the argument pointer will be set to a true value. If the configuration cache was not used, the argument pointer will be set to false.

A false value may indicates that the client will need to load the configuration from the network. This may be caused by the following:

• The configuration cache did not exist or was empty
• The configuration cache contained stale information

Argument

Modes	Arg
Get	int*

Stability

Uncommitted

LCB_CNTL_FORCE_SASL_MECH

#define LCB_CNTL_FORCE_SASL_MECH

Force a specific SASL mechanism.

Force a specific SASL mechanism to use for authentication. This can allow a user to ensure a certain level of security and have the connection fail if the desired mechanism is not available.

When setting this value, the arg parameter shall be a NUL-terminated string or a NULL pointer (to unset). When retrieving this value, the parameter shall be set to a char **. Note that this value (in LCB_CNTL_GET) is valid only until the next call to a libcouchbase API, after which it may have been freed.

Argument

Modes	Arg
Get	char**
Set	char*

LCB_CNTL_MAX_REDIRECTS

#define LCB_CNTL_MAX_REDIRECTS

Maximum number of HTTP redirects to follow Set how many redirects the library should follow for the single request.

Set to -1 to remove limit at all.

Argument

Modes	Arg
Get, Set	int*

Stability

Uncommitted

LCB_CNTL_LOGGER

#define LCB_CNTL_LOGGER

Access the lcb_LOGGER structure.

Stability

Uncommitted

The lcb_logoprocs structure passed must not be freed until the instance is completely destroyed. This will only happen once the destruction callback is called (see lcb_set_destroy_callback()).

Argument

Modes	Arg
Get	lcb_logprocs**
Set	lcb_logprocs*

LCB_CNTL_CONFDELAY_THRESH

#define LCB_CNTL_CONFDELAY_THRESH

Refresh Throttling.

Modify the amount of time (in microseconds) before the LCB_CNTL_CONFERRTHRESH will forcefully be set to its maximum number forcing a configuration refresh.

Note that if you expect a high number of timeouts in your operations, you should set this to a high number (along with CONFERRTHRESH). If you are using the default timeout setting, then this value is likely optimal.

Argument

Modes	Arg
Get, Set	lcb_U32*

See also

LCB_CNTL_CONFERRTHRESH

LCB_CNTL_CONFIG_TRANSPORT

#define LCB_CNTL_CONFIG_TRANSPORT

Get the transport used to fetch cluster configuration.

Argument

Modes	Arg
Get	lcb_config_transport_t*

Stability

Uncommitted

LCB_CNTL_CONFIG_NODE_TIMEOUT

#define LCB_CNTL_CONFIG_NODE_TIMEOUT

Per-node configuration timeout.

The per-node configuration timeout sets the amount of time to wait for each node within the bootstrap/configuration process. This interval is a subset of the LCB_CNTL_CONFIGURATION_TIMEOUT option mentioned above and is intended to ensure that the bootstrap process does not wait too long for a given node. Nodes that are physically offline may never respond and it may take a long time until they are detected as being offline. See CCBC-261 and CCBC-313 for more reasons.

Note

the CONFIGURATION_TIMEOUT should be higher than this number. No check is made to ensure that this is the case, however.

Argument

Modes	Arg
Get, Set	lcb_U32*

See also

LCB_CNTL_CONFIGURATION_TIMEOUT

Stability

Committed

LCB_CNTL_HTCONFIG_IDLE_TIMEOUT

#define LCB_CNTL_HTCONFIG_IDLE_TIMEOUT

Idling/Persistence for HTTP bootstrap.

By default the behavior of the library for HTTP bootstrap is to keep the stream open at all times (opening a new stream on a different host if the existing one is broken) in order to proactively receive configuration updates.

The default value for this setting is -1. Changing this to another number invokes the following semantics:

• The configuration stream is not kept alive indefinitely. It is kept open for the number of seconds specified in this setting. The socket is closed after a period of inactivity (indicated by this setting).
• If the stream is broken (and no current refresh was requested by the client) then a new stream is not opened.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Volatile

LCB_CNTL_CHANGESET

#define LCB_CNTL_CHANGESET

Get the current SCM changeset for the library binary.

Argument

Modes	Arg
Get	char**

LCB_CNTL_CONFIGCACHE

#define LCB_CNTL_CONFIGCACHE

File used for the configuration cache.

The configuration cache allows to bootstrap from a cluster without using the initial bootstrap connection, considerably reducing latency. If the file passed does not exist, the normal bootstrap process is performed and the file is written to with the current information. File will be updated as the configuration in the cluster changes. Multiple instances may race to update the file, and that is the intended behavior.

Note

The leading directories for the file must exist, otherwise the file will never be created.

Configuration cache is not supported for memcached buckets

Argument

Modes	Arg
Get	char**
Set	char*

Stability

Uncommitted

See also

LCB_CNTL_CONFIG_CACHE_LOADED

LCB_CNTL_CONFIGCACHE_RO

#define LCB_CNTL_CONFIGCACHE_RO

File used for read-only configuration cache.

This is identical to the LCB_CNTL_CONFIGCACHE directive, except that it guarantees that the library will never overwrite or otherwise modify the path specified.

See also

LCB_CNTL_CONFIGCACHE

LCB_CNTL_SSL_MODE

#define LCB_CNTL_SSL_MODE

Get SSL Mode.

Retrieve the SSL mode currently in use by the library. This is a read-only setting. To set the SSL mode at the library, specify the appropriate values within the connection string. See lcb_create_st3 for details.

Argument

Modes	Arg
Get	int* (value is one of lcb_SSLOPTS)

Stability

Committed

LCB_CNTL_SSL_CERT

#define LCB_CNTL_SSL_CERT

Get SSL Certificate path.

Retrieve the path to the CA certificate (if any) being used.

Argument

Modes	Arg
Get	char**

See also

LCB_CNTL_SSL_MODE

Stability

Committed

LCB_CNTL_SSL_KEY

#define LCB_CNTL_SSL_KEY

Get SSL private key path.

Retrieve the path to the private key (if any) being used. When key specified, the library will use it to authenticate on the services, skipping all other authentication mechanisms (SASL, HTTP Basic auth, etc)

Argument

Modes	Arg
Get	char**

See also

LCB_CNTL_SSL_MODE

https://developer.couchbase.com/documentation/server/5.0/security/security-certs-auth.html

Stability

Committed

LCB_CNTL_SSL_TRUSTSTORE

#define LCB_CNTL_SSL_TRUSTSTORE

Get SSL trust store path.

Trust store might be NULL, in this case the library expects it to be concatenated with certificate.

Argument

Modes	Arg
Get	char**

See also

LCB_CNTL_SSL_MODE

https://developer.couchbase.com/documentation/server/5.0/security/security-certs-auth.html

Stability

Committed

LCB_CNTL_SSL_CACERT

#define LCB_CNTL_SSL_CACERT

Alias for LCB_CNTL_SSL_CERT for backward compatibility.

Deprecated

LCB_RETRYOPT_CREATE

#define LCB_RETRYOPT_CREATE	(		mode,
			policy )

Create a retry setting value.

Parameters

mode	the mode to set (

See also

lcb_RETRYMODEOPTS)

Parameters

policy

the policy determining which commands should be retried (

See also

lcb_RETRYCMDOPTS)

Returns

a value which can be assigned to an lcb_U32 and passed to the LCB_CNTL_RETRYMODE setting

LCB_CNTL_RETRYMODE

#define LCB_CNTL_RETRYMODE

Set retry policies.

Stability

Volatile

This function sets the retry behavior. The retry behavior is the action the library should take when a command has failed because of a failure which may be a result of environmental and/or topology issues. In such cases it may be possible to retry the command internally and have it succeed a second time without propagating an error back to the application.

The behavior consists of a mode and command selectors. The command selector indicates which commands should be retried (and which should be propagated up to the user) whereas the mode indicates under which circumstances should the command policy be used.

Disable retries anywhere:

for (int ii = 0; ii < LCB_RETRY_ON_MAX; ++ii) {
  lcb_U32 val = LCB_RETRYOPT_CREATE(ii, LCB_RETRY_CMDS_NONE);
  lcb_STATUS err = lcb_cntl(instance, LCB_CNTL_SET, LCB_CNTL_RETRYMODE, &val);
}

Only retry simple GET operations when retry is needed because of topology changes:

lcb_U32 val = LCB_RETRYOPT_CREATE(LCB_RETRY_ON_TOPOCHANGE, LCB_RETRY_CMDS_GET);
lcb_cntl(instance, LCB_CNTL_SET, LCB_CNTL_RETRYMODE, &val);

Determine the behavior of the library when a NOT_MY_VBUCKET is received:

lcb_U32 val = LCB_RETRYOPT_CREATE(LCB_RETRY_ON_VBMAPERR, 0);
lcb_cntl(instance, LCB_CNTL_GET, LCB_CNTL_RETRYMODE, &val);
lcb_U32 policy = LCB_RETRYOPT_GETPOLICY(val);

Argument

Modes	Arg
Get, Set	lcb_U32 *

LCB_CNTL_HTCONFIG_URLTYPE

#define LCB_CNTL_HTCONFIG_URLTYPE

Set the URL selection mode.

The URL type can be a mask of the lcb_HTCONFIG_URLTYPE constants which indicate which URLs the HTTP provider should use.

The default is to use the 25PLUS URI first, and fallback on the compat uri if the terse one fails with an HTTP 404 (Not Found). The new-style URI is considered more efficient on cluster resources and can help the cluster maintain many more streaming connections than the compat version, however it is only available in Couchbase Server 2.5 and greater.

This setting is only used when CCCP is disabled. This will typically be for older clusters or for memcached buckets.

Argument

Modes	Arg
Get, Set	int* (value is one of lcb_HTCONFIG_URLTYPE)

Stability

Volatile

Primarily here to support tests and buggy HTTP servers/proxies which do not like to maintain a connection upon receipt of a 404.

LCB_CNTL_SYNCDESTROY

#define LCB_CNTL_SYNCDESTROY

Determines whether to run the event loop internally within lcb_destroy() until no more I/O resources remain for the library.

This is usually only necessary if you are creating a lot of instances and/or are using memory leak analysis tools.

Argument

Modes	Arg
Get, Set	int* (as a boolean)

See also

lcb_destroy_async() and lcb_set_destroy_callback()

Stability

Volatile

LCB_CNTL_CONLOGGER_LEVEL

#define LCB_CNTL_CONLOGGER_LEVEL

Sets the logging level for the console logger.

If a logger is already initialized (either from the environment, or via lcb_cntl_logger() then this operation does nothing.

This is mainly useful for applications which want to proxy the built in logging options via command line options and the like, rather than setting it from the environment.

The argument passed to lcb_cntl() is an integer of 0 until LCB_LOG_MAX, though the actual type is of lcb_U32 rather than an enum type #lcb_log_severity_t.

Argument

Modes	Arg
Set	const lcb_U32 *

See also

LCB_CNTL_LOGGER

LCB_CNTL_CONLOGGER_FP

#define LCB_CNTL_CONLOGGER_FP

Sets the output file (as a FILE*) for the console logger.

Note that any existing file pointer will be cleared (but not fclose()d.

If used with lcb_cntl_string(), (using the console_log_file parameter), the third argument is taken as the name of a file. Note that the user is responsible for closing the file.

This setting does not require a library handle and therefore the first argument to lcb_cntl() should be NULL.

Argument

Modes	Arg
Get	FILE**
Set	FILE*

See also

LCB_CNTL_LOGGER

LCB_CNTL_CONLOGGER_LEVEL

LCB_CNTL_DETAILED_ERRCODES

#define LCB_CNTL_DETAILED_ERRCODES

Sets the behavior for reporting network errors.

By default network errors are returned as LCB_ERR_NETWORK return codes for compatibility reasons. More detailed error codes may be available by enabling this option which will return appropriate error codes which have a category of LCB_ERRTYPE_NETWORK

Using this option means your programming model is centered around the various LCB_EIF* macros (see <libcouchbase/error.h>) rather than individual codes.

Argument

Modes	Arg
Get, Set	int * (As a boolean)

LCB_CNTL_RETRY_INTERVAL

#define LCB_CNTL_RETRY_INTERVAL

Sets the interval at which the retry queue will attempt to resend a failed operation.

When an operation fails and the retry policy (see LCB_CNTL_RETRYMODE) allows the operation to be retried, it shall be placed into a queue, and then be retried within a given interval.

Setting a high value will be friendlier on the network but also potentially increase latency, while setting this to a low value may cause unnecessary network traffic for operations which are not yet ready to be retried.

Argument

Modes	Arg
Get, Set	lcb_U32* (microseconds)

LCB_CNTL_RETRY_NMV_IMM

#define LCB_CNTL_RETRY_NMV_IMM

Whether commands are retried immediately upon receipt of not-my-vbucket replies.

Since version 2.4.8, packets by default are retried immediately on a different node if it had previously failed with a not-my-vbucket response, and is thus not subject to the LCB_CNTL_RETRY_INTERVAL setting. Disabling this setting will restore the older behavior. This may be used in case there are problems with the default heuristic/retry algorithm.

Stability

Volatile

LCB_CNTL_HTTP_POOLSIZE

#define LCB_CNTL_HTTP_POOLSIZE

Set the maximum pool size for pooled http (view request) sockets.

This should be set to 1 (the default) unless you plan to execute concurrent view requests. You may set this to 0 to disable pooling

Argument

Modes	Arg
Get, Set	lcb_SIZE

Stability

Volatile

LCB_CNTL_HTTP_REFRESH_CONFIG_ON_ERROR

#define LCB_CNTL_HTTP_REFRESH_CONFIG_ON_ERROR

Determine whether or not a new configuration should be received when an error is received over the HTTP API (i.e.

via lcb_make_http_request().

The default value is true, however you may wish to disable this if you are expectedly issuing a lot of requests which may result in an error.

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Uncommitted

LCB_CNTL_SCHED_IMPLICIT_FLUSH

#define LCB_CNTL_SCHED_IMPLICIT_FLUSH

Set the behavior of the lcb_sched_leave() API call.

By default the lcb_sched_leave() will also set up the necessary requirements for flushing to the network. If this option is off then an explicit call to lcb_sched_flush() must be performed instead.

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Volatile

LCB_CNTL_ENABLE_MUTATION_TOKENS

#define LCB_CNTL_ENABLE_MUTATION_TOKENS

Request the server to return an additional 16 bytes of data for each mutation operation.

This extra information may help with more reliable durability polling, but will also increase the size of the response packet.

This should be set on the instance before issuing lcb_connect(). While this may also be set after lcb_connect() is called, it will currently only take effect when a server reconnects (which itself may be undefined).

Argument

Modes	Arg
Get, Set	int (as boolean)

LCB_CNTL_MUTATION_TOKENS_SUPPORTED

#define LCB_CNTL_MUTATION_TOKENS_SUPPORTED

This read-only property determines if the mutation token mechanism is supported on the cluster itself.

This will only be accurate once a single operation has been performed on the cluster - or in other words, once a connection to a data node has been established for the purposes of normal operations.

Argument

Modes	Arg
Get	int (as boolean)

Stability

Uncommitted

LCB_CNTL_RESET_TIMEOUT_ON_WAIT

#define LCB_CNTL_RESET_TIMEOUT_ON_WAIT

This setting determines if calls to lcb_wait() and lcb_wait() will reset the timeout of pending operations to the time that lcb_wait() was called, rather than having the operation maintain the time of the call which scheduled it.

If the time between lcb_store3() and family and the lcb_wait() functions is long, it is recommended to disable this setting in order to avoid prematurely having operations time out.

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Uncommitted

Use "readj_wait_tmo" for the string version

LCB_CNTL_QUERY_CLEARACHE

#define LCB_CNTL_QUERY_CLEARACHE

Clears the internal prepared statement cache for N1QL.

This does not take any arguments, and is valid only on LCB_CNTL_SET

Stability

Uncommitted

LCB_CNTL_CLIENT_STRING

#define LCB_CNTL_CLIENT_STRING

Sets additional text for negotiation.

This allows wrappers or applications to add additional identifying information which can then be seen in the server logs.

Argument

Modes	Arg
Get	const char**
Set	const char*

Use "client_string" for the string version

LCB_CNTL_BUCKET_CRED

#define LCB_CNTL_BUCKET_CRED

Set credentials for a bucket.

This is used for N1QL and CBFT APIs to allow access to multiple buckets. It can also be used to set the password of the current bucket when reconnecting (in case it changes).

The format for the credentials is an array of two nul-terminated strings, the first refers to the bucket and the second refers to the password.

LCB_CNTL_RETRY_NMV_INTERVAL

#define LCB_CNTL_RETRY_NMV_INTERVAL

Set the amount of time the client should wait before retrying a not-my-vbucket response packet.

The default is 100ms. The value should be specified in microseconds.

Use "retry_nmv_interval" with lcb_cntl_string()

Argument

Modes	Arg
Get, Set	lcb_U32*

LCB_CNTL_READ_CHUNKSIZE

#define LCB_CNTL_READ_CHUNKSIZE

Limit the number of bytes to be read (and thereby processed) during I/O read operations.

This setting may be useful when the network is faster than processing resources.

Note

This setting only works for event-style I/O plugins. This means it has no effect on completion style plugins such as libuv or Windows IOCP

Argument

Modes	Arg
Get, Set	lcb_U32*

LCB_CNTL_SELECT_BUCKET

#define LCB_CNTL_SELECT_BUCKET

Enable/Disable sending the SELECT_BUCKET command after authentication.

This is useful to test auth, and should not be set by end-users.

Note that even if this feature is enabled (the default), the client will only send SELECT_BUCKET if the server indicates that it is supported during negotiation.

Use select_bucket in the connection string

Argument

Modes	Arg
Get, Set	int* (as boolean)

LCB_CNTL_TCP_KEEPALIVE

#define LCB_CNTL_TCP_KEEPALIVE

Enable/Disable setting the TCP_KEEPALIVE option on created sockets.

This is enabled by default for I/O backends which support it.

The keepalive interval will be set to the operating system default.

Argument

Modes	Arg
Get, Set	int* (as boolean)

LCB_CNTL_CONFIG_POLL_INTERVAL

#define LCB_CNTL_CONFIG_POLL_INTERVAL

Set the amount of time to wait in between polling for a new configuration.

This will have no effect if connected to a Memcached buckets, or using HTTP or File-based configurations (see the bootstrap_on connection string option).

This option facilitates 'fast failover' - in that the client can preemptively check for any cluster topology updates before encountering an error.

Argument

Modes	Arg
Get, Set	lcb_U32*

The value for this option is a time value. See the top of this header in respect to how to specify this.

Using a value of 0 disables this feature.

You can also use config_poll_interval in the connection string.

Note

Background polling is implemented in the library's non-blocking event loop. Synchronous clients (i.e. those using lcb_wait()) will only be able to poll as often as the library's event loop is active. If the library is suspended, that is, if not inside an lcb_wait() call, the library will be unable to do any kind of background polling.

LCB_CNTL_LOG_REDACTION

#define LCB_CNTL_LOG_REDACTION

Once redaction is enabled, anything at ERROR, WARN and INFO will wrap sensitive information with special tags, for further processing with the goal to remove or encrypt that information.

DEBUG or TRACE level logging are expected to have specific info.

Use log_redaction in the connection string

Argument

Modes	Arg
Get, Set	int* (as boolean)

Stability

Committed

LCB_CNTL_ENABLE_TRACING

#define LCB_CNTL_ENABLE_TRACING

Activate/deactivate end-to-end tracing.

Use enable_tracing in the connection string

Argument

Modes	Arg
Get, Set	int* (as boolean)

See also

lcb-tracing-api

Stability

Committed

LCB_CNTL_TRACING_ORPHANED_QUEUE_FLUSH_INTERVAL

#define LCB_CNTL_TRACING_ORPHANED_QUEUE_FLUSH_INTERVAL

Flush interval for orphaned spans queue in default tracer.

This is the time the tracer will wait between repeated attempts to flush most recent orphaned spans.

Use tracing_orphaned_queue_flush_interval in the connection string

lcb_U32 tmo = 10000000; // 10 seconds in microseconds
lcb_cntl(instance, LCB_CNTL_SET, LCB_CNTL_TRACING_ORPHANED_QUEUE_FLUSH_INTERVAL, &tmo);

rv = lcb_cntl_string("tracing_orphaned_queue_flush_interval", "10.0");

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_ORPHANED_QUEUE_SIZE

#define LCB_CNTL_TRACING_ORPHANED_QUEUE_SIZE

Size of orphaned spans queue in default tracer.

Queues in default tracer has fixed size, and it will remove information about older spans, when the limit will be reached before flushing time.

Use tracing_orphaned_queue_size in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_QUEUE_FLUSH_INTERVAL

#define LCB_CNTL_TRACING_THRESHOLD_QUEUE_FLUSH_INTERVAL

Flush interval for spans with total time over threshold in default tracer.

This is the time the tracer will wait between repeated attempts to flush threshold queue.

Use tracing_threshold_queue_flush_interval in the connection string

lcb_U32 tmo = 10000000; // 10 seconds in microseconds
lcb_cntl(instance, LCB_CNTL_SET, LCB_CNTL_TRACING_THRESHOLD_QUEUE_FLUSH_INTERVAL, &tmo);

rv = lcb_cntl_string("tracing_threshold_queue_flush_interval", "10.0");

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_QUEUE_SIZE

#define LCB_CNTL_TRACING_THRESHOLD_QUEUE_SIZE

Size of threshold queue in default tracer.

Queues in default tracer has fixed size, and it will remove information about older spans, when the limit will be reached before flushing time.

Use tracing_threshold_queue_size in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_KV

#define LCB_CNTL_TRACING_THRESHOLD_KV

Minimum time for the tracing span of KV service to be considered by threshold tracer.

Use tracing_threshold_kv in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_QUERY

#define LCB_CNTL_TRACING_THRESHOLD_QUERY

Minimum time for the tracing span of N1QL service to be considered by threshold tracer.

Use tracing_threshold_query in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_VIEW

#define LCB_CNTL_TRACING_THRESHOLD_VIEW

Minimum time for the tracing span of VIEW service to be considered by threshold tracer.

Use tracing_threshold_view in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_SEARCH

#define LCB_CNTL_TRACING_THRESHOLD_SEARCH

Minimum time for the tracing span of FTS service to be considered by threshold tracer.

Use tracing_threshold_search in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_TRACING_THRESHOLD_ANALYTICS

#define LCB_CNTL_TRACING_THRESHOLD_ANALYTICS

Minimum time for the tracing span of ANALYTICS service to be considered by threshold tracer.

Use tracing_threshold_analytics in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_COMPRESSION_OPTS

#define LCB_CNTL_COMPRESSION_OPTS

Control how the library handles compression and deflation to and from the server.

Starting in Couchbase Server 3.0, compression can optionally be applied to incoming and outcoming data. For incoming (i.e. GET requests) the data may be received in compressed format and then allow the client to inflate the data upon receipt. For outgoing (i.e. SET requests) the data may be compressed on the client side and then be stored and recognized on the server itself.

The default behavior is to transparently handle compression for both incoming and outgoing data.

Note that if the lcb_STORECMDv0::datatype field is set with compression flags, the data will never be compressed by the library as this is an indication that it is already compressed.

Argument

Modes	Arg
Get, Set	int* (value is one of lcb_COMPRESSOPTS)

Stability

Committed

LCB_CNTL_COMPRESSION_MIN_SIZE

#define LCB_CNTL_COMPRESSION_MIN_SIZE

Minimum size of the document payload to be compressed when compression enabled.

Use compression_min_size in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_COMPRESSION_MIN_RATIO

#define LCB_CNTL_COMPRESSION_MIN_RATIO

Minimum compression ratio (compressed / original) of the compressed payload to allow sending it to cluster.

Use compression_min_ratio in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_NETWORK

#define LCB_CNTL_NETWORK

Select type of network (alternative addresses).

Use network in the connection string

Argument

Modes	Arg
Get	const char**
Set	const char*

Stability

Uncommitted

LCB_CNTL_HTTP_POOL_TIMEOUT

#define LCB_CNTL_HTTP_POOL_TIMEOUT

The amount of time the pool should wait before closing idle connections.

Use http_pool_timeout in the connection string

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_ENABLE_COLLECTIONS

#define LCB_CNTL_ENABLE_COLLECTIONS

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Volatile

LCB_CNTL_ENABLE_DURABLE_WRITE

#define LCB_CNTL_ENABLE_DURABLE_WRITE

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Volatile

LCB_CNTL_PERSISTENCE_TIMEOUT_FLOOR

#define LCB_CNTL_PERSISTENCE_TIMEOUT_FLOOR

Stability

Volatile

LCB_CNTL_ALLOW_STATIC_CONFIG

#define LCB_CNTL_ALLOW_STATIC_CONFIG

Stability

Volatile

LCB_CNTL_ANALYTICS_TIMEOUT

#define LCB_CNTL_ANALYTICS_TIMEOUT

Analytics Timeout This is the global I/O timeout for Analytics queries, issued via lcb_analytics()

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_ENABLE_UNORDERED_EXECUTION

#define LCB_CNTL_ENABLE_UNORDERED_EXECUTION

Tell the server that the library supports reordering the execution of the commands.

Argument

Modes	Arg
Get, Set	int (as boolean)

Stability

Volatile

LCB_CNTL_SEARCH_TIMEOUT

#define LCB_CNTL_SEARCH_TIMEOUT

Search Timeout This is the global I/O timeout for Search queries, issued via lcb_search()

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_ENABLE_ERRMAP

#define LCB_CNTL_ENABLE_ERRMAP

Enable/Disable the Error Map feature.

This is disabled by default. Works only on servers which support error map

Use enable_errmap in the connection string

Argument

Modes	Arg
Get, Set	int* (as boolean)

LCB_CNTL_OP_METRICS_FLUSH_INTERVAL

#define LCB_CNTL_OP_METRICS_FLUSH_INTERVAL

Flush interval for the per-operation metrics to be output to the logs.

This is the time the metrics collector will wait between repeated attempts to flush the operation metrics. Note this only applies to the default metrics collector.

Use operation_metrics_flush_interval in the connection string.

Argument

Modes	Arg
Get, Set	lcb_U32*

Stability

Committed

LCB_CNTL_ENABLE_OP_METRICS

#define LCB_CNTL_ENABLE_OP_METRICS

Enable/disable per-operation metrics collection.

This will enable or disable the operation metrics collection. The default metrics collection will output histograms of the latency for each operation to stderr. A custom metrics collector can be specified as well, which could be used to aggregate and output to a variety of different systems.

Use enable_operation_metrics in the connection string.

Stability

Committed

Argument

Modes	Arg
Get, Set	int* (as boolean)

LCB_CNTL_PREFERRED_SERVER_GROUP

#define LCB_CNTL_PREFERRED_SERVER_GROUP

Select server group to use for replica APIs.

For some use-cases it might be necessary to restrict list of the nodes, that are used in replica read APIs to single server group to optimize network costs.

Use preferred_server_group in the connection string.

Stability

Committed

Argument

Modes	Arg
Get, Set	const char*

See also

https://docs.couchbase.com/server/current/manage/manage-groups/manage-groups.html

LCB_CNTL__MAX

#define LCB_CNTL__MAX

This is not a command, but rather an indicator of the last item.

Stability

Internal

Enumeration Type Documentation

lcb_ipv6_t

enum lcb_ipv6_t

Modes for handling IPv6 in the IO layer.

Enumerator
LCB_IPV6_DISABLED	disable IPv6
LCB_IPV6_ONLY	enforce only IPv6
LCB_IPV6_ALLOW	use both IPv6 and IPv4

lcb_SSLOPTS

enum lcb_SSLOPTS

SSL options.

Stability

Committed

Enumerator
LCB_SSL_ENABLED	Use SSL.
LCB_SSL_NOVERIFY	Don't verify certificates.
LCB_SSL_NOGLOBALINIT	Do not call SSL's global init functions.

lcb_RETRYMODEOPTS

enum lcb_RETRYMODEOPTS

Select retry mode to manipulate.

Enumerator
LCB_RETRY_ON_TOPOCHANGE	Select retry for topology.
LCB_RETRY_ON_SOCKERR	Select retry for network errors.
LCB_RETRY_ON_VBMAPERR	Select retry for NOT_MY_VBUCKET responses.
LCB_RETRY_ON_MISSINGNODE	Retry when there is no node for the item. This case is special as the cmd setting is treated as a boolean rather than a bitmask
LCB_RETRY_ON_MAX	< maximum index

lcb_RETRYCMDOPTS

enum lcb_RETRYCMDOPTS

Enumerator
LCB_RETRY_CMDS_NONE	Don't retry any commands. A command which has been forwarded to a server and a not-my-vbucket has been received in response for it will result in a failure.
LCB_RETRY_CMDS_GET	Only retry simple retrieval operations (excludes touch, get-and-touch, and get-locked) which may be retried many numbers of times without risking unintended data manipulation.
LCB_RETRY_CMDS_SAFE	Retry operations which may potentially fail because they have been accepted by a previous server, but will not silently corrupt data. Such commands include mutation operations containing a CAS.
LCB_RETRY_CMDS_ALL	Retry all commands, disregarding any potential unintended receipt of errors or data mutation.

lcb_HTCONFIG_URLTYPE

enum lcb_HTCONFIG_URLTYPE

Enumeration representing various URL forms to use for the configuration stream.

Enumerator
LCB_HTCONFIG_URLTYPE_25PLUS	/pools/default/b[s]/$bucket: Introduced in Couchbase Server 2.5
LCB_HTCONFIG_URLTYPE_COMPAT	/pools/default/buckets[Streaming]/$bucket.
LCB_HTCONFIG_URLTYPE_TRYALL	Try 25PLUS first and fallback to COMPAT

lcb_COMPRESSOPTS

enum lcb_COMPRESSOPTS

Options for how to handle compression.

Stability

Committed

Enumerator
LCB_COMPRESS_NONE	Do not perform compression in any direction. Data which is received compressed via the server will be indicated as such by having the LCB_VALUE_F_SNAPPYCOMP flag set in the lcb_GETRESPv0::datatype field
LCB_COMPRESS_IN	Decompress incoming data, if the data has been compressed at the server. If this is set, the datatype field in responses will always be stripped of the LCB_VALUE_F_SNAPPYCOMP flag.
LCB_COMPRESS_OUT	Compress outgoing data. Note that if the datatype field contains the LCB_VALUE_F_SNAPPYCOMP flag, then the data will never be compressed as it is assumed that it is already compressed.
LCB_COMPRESS_FORCE	By default the library will send a HELLO command to the server to determine whether compression is supported or not. Because commands may be pipelined prior to the scheduing of the HELLO command it is possible that the first few commands may not be compressed when schedule due to the library not yet having negotiated settings with the server. Setting this flag will force the client to assume that all servers support compression despite a HELLO not having been intially negotiated.