Couchbase C Client  2.7.7
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;
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 Settings

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).

Timeouts are specified in microseconds stored within an lcb_U32.

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.

Macros

#define LCB_CNTL_OP_TIMEOUT
 Operation Timeout. More...
 
#define LCB_CNTL_VIEW_TIMEOUT
 Views Timeout This is the I/O timeout for HTTP requests issues with LCB_HTTP_TYPE_VIEWS. More...
 
#define LCB_CNTL_N1QL_TIMEOUT
 N1QL Timeout This is the I/O timeout for N1QL queries, issued via lcb_n1ql_query() More...
 
#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. More...
 
#define LCB_CNTL_BUCKETTYPE
 Get the bucket type. More...
 
#define LCB_CNTL_HANDLETYPE
 Get the handle type. More...
 
#define LCB_CNTL_VBCONFIG
 Get the vBucket handle. More...
 
#define LCB_CNTL_IOPS
 Get the iops implementation instance. More...
 
#define LCB_CNTL_VBMAP
 Get the vBucket ID for a given key, based on the current configuration. More...
 
#define LCB_CNTL_CONFERRTHRESH
 Configuration error threshold. More...
 
#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. More...
 
#define LCB_CNTL_DURABILITY_INTERVAL
 Polling grace interval for lcb_durability_poll() More...
 
#define LCB_CNTL_HTTP_TIMEOUT
 Timeout for non-views HTTP requests. More...
 
#define LCB_CNTL_IOPS_DLOPEN_DEBUG
 Print verbose plugin load information to console. More...
 
#define LCB_CNTL_CONFIGURATION_TIMEOUT
 Initial bootstrap timeout. More...
 
#define LCB_CNTL_RANDOMIZE_BOOTSTRAP_HOSTS
 Randomize order of bootstrap nodes. More...
 
#define LCB_CNTL_CONFIG_CACHE_LOADED
 Determine if file-based configuration has been loaded. More...
 
#define LCB_CNTL_FORCE_SASL_MECH
 Force a specific SASL mechanism. More...
 
#define LCB_CNTL_MAX_REDIRECTS
 Maximum number of HTTP redirects to follow Set how many redirects the library should follow for the single request. More...
 
#define LCB_CNTL_CONFDELAY_THRESH
 Refresh Throttling. More...
 
#define LCB_CNTL_CONFIG_TRANSPORT
 Get the transport used to fetch cluster configuration. More...
 
#define LCB_CNTL_CONFIG_NODE_TIMEOUT
 Per-node configuration timeout. More...
 
#define LCB_CNTL_HTCONFIG_IDLE_TIMEOUT
 Idling/Persistence for HTTP bootstrap. More...
 
#define LCB_CNTL_CHANGESET
 Get the current SCM changeset for the library binary. More...
 
#define LCB_CNTL_CONFIGCACHE
 file used for the configuration cache. More...
 
#define LCB_CNTL_CONFIGCACHE_RO
 File used for read-only configuration cache. More...
 
#define LCB_CNTL_SSL_MODE
 Get SSL Mode. More...
 
#define LCB_CNTL_SSL_CERT
 Get SSL Certificate path. More...
 
#define LCB_CNTL_SSL_CACERT
 
#define LCB_RETRYOPT_CREATE(mode, policy)
 Create a retry setting value. More...
 
#define LCB_RETRYOPT_GETMODE(u)
 
#define LCB_RETRYOPT_GETPOLICY(u)
 
#define LCB_CNTL_RETRYMODE
 Set retry policies. More...
 
#define LCB_CNTL_HTCONFIG_URLTYPE
 Set the URL selection mode. More...
 
#define LCB_CNTL_SYNCDESTROY
 
#define LCB_CNTL_CONLOGGER_LEVEL
 
#define LCB_CNTL_CONLOGGER_FP
 
#define LCB_CNTL_DETAILED_ERRCODES
 
#define LCB_CNTL_RETRY_INTERVAL
 
#define LCB_CNTL_RETRY_BACKOFF
 
#define LCB_CNTL_RETRY_NMV_IMM
 
#define LCB_CNTL_HTTP_POOLSIZE
 
#define LCB_CNTL_HTTP_REFRESH_CONFIG_ON_ERROR
 uncommitted Determine whether or not a new configuration should be received when an error is received over the HTTP API (i.e. More...
 
#define LCB_CNTL_SCHED_IMPLICIT_FLUSH
 
#define LCB_CNTL_FETCH_MUTATION_TOKENS
 
#define LCB_CNTL_DURABILITY_MUTATION_TOKENS
 
#define LCB_CNTL_MUTATION_TOKENS_SUPPORTED
 
#define LCB_CNTL_RESET_TIMEOUT_ON_WAIT
 
#define LCB_CNTL_N1QL_CLEARACHE
 
#define LCB_CNTL_CLIENT_STRING
 
#define LCB_CNTL_BUCKET_CRED
 Set credentials for a bucket. More...
 
#define LCB_CNTL_RETRY_NMV_INTERVAL
 Set the amount of time the client should wait before retrying a not-my-vbucket response packet. More...
 
#define LCB_CNTL_READ_CHUNKSIZE
 Limit the number of bytes to be read (and thereby processed) during I/O read operations. More...
 
#define LCB_CNTL_ENABLE_ERRMAP
 Enable/Disable the Error Map feature. More...
 
#define LCB_CNTL_SELECT_BUCKET
 Enable/Disable sending the SELECT_BUCKET command after authentication. More...
 
#define LCB_CNTL_TCP_KEEPALIVE
 Enable/Disable setting the TCP_KEEPALIVE option on created sockets. More...
 
#define LCB_CNTL_CONFIG_POLL_INTERVAL
 Set the amount of time to wait in between polling for a new configuration. More...
 
#define LCB_CNTL_SEND_HELLO
 From version 2.7.4, the C library sends a HELLO command before authentication. More...
 
#define LCB_CNTL__MAX
 This is not a command, but rather an indicator of the last item.
 

Typedefs

typedef const char * lcb_BUCKETCRED[2]
 

Enumerations

enum  lcb_SSLOPTS
 
enum  lcb_RETRYMODEOPTS
 Select retry mode to manipulate. More...
 
enum  lcb_RETRYCMDOPTS
 
enum  lcb_HTCONFIG_URLTYPE
 Enumeration representing various URL forms to use for the configuration stream. More...
 

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.

enum  lcb_log_severity_t
 Logging Levels.
 
typedef void(* lcb_logging_callback) (struct lcb_logprocs_st *procs, unsigned int iid, const char *subsys, int severity, const char *srcfile, int srcline, const char *fmt, va_list ap)
 Logger callback. More...
 
#define LCB_CNTL_LOGGER
 Access the lcb_logprocs structure. More...
 

Data Structure Documentation

◆ 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

◆ 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

◆ lcb_logprocs

struct lcb_logprocs

Logging context.

Stability
Uncommitted:

This structure defines the logging handlers. Currently there is only a single field defined which is the default callback for the loggers. This API may change.

Data Fields
int version
union lcb_logprocs v

Macro Definition Documentation

◆ 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;
Argument
ModesArg
Get, SetlcbU32*
Stability
Committed:
See also
lcb-timeout-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
ModesArg
Get, Setlcb_U32*
Stability
Committed:

◆ LCB_CNTL_N1QL_TIMEOUT

#define LCB_CNTL_N1QL_TIMEOUT

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

Argument
ModesArg
Get, Setlcb_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
ModesArg
Getconst char*
Stability
Committed:

◆ 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/5.0/architecture/core-data-access-buckets.html
Argument
ModesArg
Getlcb_BTYPE*
Stability
Uncommitted:

◆ 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
ModesArg
Getlcb_type_t*
Stability
Uncommitted:

◆ LCB_CNTL_VBCONFIG

#define LCB_CNTL_VBCONFIG

Get the vBucket handle.

Obtains the current cluster configuration from the client.

Argument
ModesArg
Getlcbvb_CONFIG**
Stability
Uncommitted:

◆ LCB_CNTL_IOPS

#define LCB_CNTL_IOPS

Get the iops implementation instance.

Argument
ModesArg
Getlcb_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
ModesArg
Getlcb_cntl_vbinfo_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
ModesArg
Get, Setlcb_SIZE*
Stability
Uncommitted:

◆ 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
ModesArg
Get, Setlcb_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
ModesArg
Get, Setlcb_U32*
Stability
Committed:

◆ LCB_CNTL_HTTP_TIMEOUT

#define LCB_CNTL_HTTP_TIMEOUT

Timeout for non-views HTTP requests.

Argument
ModesArg
Get, Setlcb_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
ModesArg
Get, Setint*
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
ModesArg
Get, Setlcb_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
ModesArg
Get, Setint*
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
ModesArg
Getint*
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
ModesArg
Getchar**
Setchar*
Stability
Uncommitted:

◆ 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
ModesArg
Get, Setint*
Stability
Uncommitted:

◆ LCB_CNTL_LOGGER

#define LCB_CNTL_LOGGER

Access the lcb_logprocs 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
ModesArg
Getlcb_logprocs**
Setlcb_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
ModesArg
Get, Setlcb_U32*
See also
LCB_CNTL_CONFERRTHRESH
Stability
Uncommitted:

◆ LCB_CNTL_CONFIG_TRANSPORT

#define LCB_CNTL_CONFIG_TRANSPORT

Get the transport used to fetch cluster configuration.

Argument
ModesArg
Getlcb_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
ModesArg
Get, Setlcb_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
ModesArg
Get, Setlcb_U32*
Stability
Volatile:

◆ LCB_CNTL_CHANGESET

#define LCB_CNTL_CHANGESET

Get the current SCM changeset for the library binary.

Argument
ModesArg
Getchar**
Stability
Committed:

◆ 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.

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
ModesArg
Getchar**
Setchar*
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
ModesArg
Getint* (value is one of lcb_SSLOPTS)

◆ 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
ModesArg
Getchar**
See also
LCB_CNTL_SSL_MODE

◆ LCB_RETRYOPT_CREATE

#define LCB_RETRYOPT_CREATE (   mode,
  policy 
)

Create a retry setting value.

Parameters
modethe mode to set (
See also
lcb_RETRYMODEOPTS)
Parameters
policythe 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) {
}

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

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

lcb_U32 policy = LCB_RETRYOPT_GETPOLICY(val);
Argument
ModesArg
Get, Setlcb_U32 *

◆ LCB_CNTL_HTCONFIG_URLTYPE

#define LCB_CNTL_HTCONFIG_URLTYPE

Set the URL selection mode.

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.

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
ModesArg
Get, Setint* (value is one of lcb_HTCONFIG_URLTYPE)

◆ LCB_CNTL_SYNCDESTROY

#define LCB_CNTL_SYNCDESTROY
Stability
Volatile:
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
ModesArg
Get, Setint* (as a boolean)
See also
lcb_destroy_async() and lcb_set_destroy_callback()

◆ LCB_CNTL_CONLOGGER_LEVEL

#define LCB_CNTL_CONLOGGER_LEVEL
Stability
Committed:

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_LOGLEVEL_MAX, though the actual type is of lcb_U32 rather than an enum type.

Argument
ModesArg
Setconst lcb_U32 *
See also
LCB_CNTL_LOGGER

◆ LCB_CNTL_CONLOGGER_FP

#define LCB_CNTL_CONLOGGER_FP
Stability
Uncommitted:

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
ModesArg
GetFILE**
SetFILE*
See also
LCB_CNTL_LOGGER
LCB_CNTL_CONLOGGER_LEVEL

◆ LCB_CNTL_DETAILED_ERRCODES

#define LCB_CNTL_DETAILED_ERRCODES
Stability
Committed:

Sets the behavior for reporting network errors. By default network errors are returned as LCB_NETWORK_ERROR 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
ModesArg
Get, Setint * (As a boolean)

◆ LCB_CNTL_RETRY_INTERVAL

#define LCB_CNTL_RETRY_INTERVAL
Stability
Uncommitted:

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
ModesArg
Get, Setlcb_U32* (microseconds)
See also
LCB_CNTL_RETRY_BACKOFF

◆ LCB_CNTL_RETRY_BACKOFF

#define LCB_CNTL_RETRY_BACKOFF
Stability
Uncommitted:

When an operation has been retried more than once and it has still not succeeded, the library will attempt to back off for the operation by scheduling it to be retried in LCB_CNTL_RETRY_INTEVAL * ${n} microseconds, where ${n} is the factor controlled by this setting.

Argument
ModesArg
Get, Setfloat*

◆ LCB_CNTL_RETRY_NMV_IMM

#define LCB_CNTL_RETRY_NMV_IMM
Stability
Volatile:
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 and LCB_CNTL_RETRY_BACKOFF settings. Disabling this setting will restore the older behavior. This may be used in case there are problems with the default heuristic/retry algorithm.

◆ LCB_CNTL_HTTP_POOLSIZE

#define LCB_CNTL_HTTP_POOLSIZE
Stability
Volatile:

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
ModesArg
Get, Setlcb_SIZE

◆ LCB_CNTL_HTTP_REFRESH_CONFIG_ON_ERROR

#define LCB_CNTL_HTTP_REFRESH_CONFIG_ON_ERROR

uncommitted 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
ModesArg
Get, Setint (as boolean)

◆ LCB_CNTL_SCHED_IMPLICIT_FLUSH

#define LCB_CNTL_SCHED_IMPLICIT_FLUSH
Stability
Volatile:
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
ModesArg
Get, Setint (as boolean)

◆ LCB_CNTL_FETCH_MUTATION_TOKENS

#define LCB_CNTL_FETCH_MUTATION_TOKENS
Stability
Volatile:

Allow 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
ModesArg
Get, Setint (as boolean)

◆ LCB_CNTL_DURABILITY_MUTATION_TOKENS

#define LCB_CNTL_DURABILITY_MUTATION_TOKENS
Stability
Volatile:

This setting determines whether the lcb_durability_poll() function will transparently attempt to use mutation token functionality (rather than checking the CAS). This option is most useful for older code which does explicitly use mutation tokens but would like to use its benefits when ensuring durability constraints are satisfied.

This option is enabled by default. Users may wish to disable this if they are performing durability operations against items stored from different client instances, as this will make use of a client-global state which is derived on a per-vBucket basis. This means that the last mutation performed on a given vBucket for the client will be used, which in some cases may be older or newer than the mutations passed to the lcb_durability_poll() function.

Argument
ModesArg
Get, Setint (as boolean)

◆ LCB_CNTL_MUTATION_TOKENS_SUPPORTED

#define LCB_CNTL_MUTATION_TOKENS_SUPPORTED
Stability
Volatile:

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
ModesArg
Getint (as boolean)

◆ LCB_CNTL_RESET_TIMEOUT_ON_WAIT

#define LCB_CNTL_RESET_TIMEOUT_ON_WAIT
Stability
Uncommitted:
This setting determines if calls to lcb_wait() and lcb_wait3() 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
ModesArg
Get, Setint (as boolean)
Use "readj_wait_tmo" for the string version

◆ LCB_CNTL_N1QL_CLEARACHE

#define LCB_CNTL_N1QL_CLEARACHE
Stability
Volatile:
Clears the internal prepared statement cache for N1QL

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

◆ LCB_CNTL_CLIENT_STRING

#define LCB_CNTL_CLIENT_STRING
Stability
Committed:
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
ModesArg
Getconst char**
Setconst 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

Stability
Committed:
Argument
ModesArg
Get, Setlcb_U32*
Use "retry_nmv_interval" with lcb_cntl_string()

◆ 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
Stability
Committed:
Argument
ModesArg
Get, Setlcb_U32*

◆ 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

Stability
Volatile:
Argument
ModesArg
Get, Setint* (as boolean)

◆ 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

Stability
Volatile:
Argument
ModesArg
Get, Setint* (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.

Stability
Committed:
Argument
ModesArg
Get, Setint* (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.

Stability
Volatile:
Argument
ModesArg
Get, Setlcb_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_SEND_HELLO

#define LCB_CNTL_SEND_HELLO

From version 2.7.4, the C library sends a HELLO command before authentication.

This works on all modern server versions, but may cause disconnects on more ancient variants (Couchbase 2.x for example).

This setting will disable the sending of the HELLO command (which older servers don't understand anyway). To disable the sending of hello, set this value to false.

Stability
Uncommitted:
Argument
ModesArg
Get, Setint* (as boolean)
You can also use send_hello=false in the connection string.

Typedef Documentation

◆ lcb_logging_callback

typedef void(* lcb_logging_callback) (struct lcb_logprocs_st *procs, unsigned int iid, const char *subsys, int severity, const char *srcfile, int srcline, const char *fmt, va_list ap)

Logger callback.

Stability
Uncommitted:

This callback is invoked for each logging message emitted

Parameters
procsthe logging structure provided
iidinstance id
subsysa string describing the module which emitted the message
severityone of the LCB_LOG_* severity constants.
srcfilethe source file which emitted this message
srclinethe line of the file for the message
fmta printf format string
apa va_list for vprintf

Enumeration Type Documentation

◆ lcb_SSLOPTS

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

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

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

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