fdb v5.1.7-5 FDB.Option View Source
This module contains all the options that are accepted by various functions. These options are autogenerated from xml file.
Link to this section Summary
Functions
Used to add a read conflict range
Used to add a write conflict range
Hexadecimal ID
Max location cache entries
Hexadecimal ID
Max outstanding watches
Returns true
if the error indicates the transaction may have succeeded, though not in a way the system can verify
Returns true
if the error indicates the operations in the transactions should be retried because of transient error
Returns true
if the error indicates the transaction has not committed, though in a way that can be retried
addend
value with which to perform bitwise and
value to append to the database value
value with which to perform bitwise and
value with which to perform bitwise or
value with which to perform bitwise xor
value to check against database value
value to check against database value
value to check against database value
value to check against database value
value with which to perform bitwise or
value to which to set the transformed key
value to versionstamp and set
value with which to perform bitwise xor
probability expressed as a percentage between 0 and 100
probability expressed as a percentage between 0 and 100
If set, callbacks from external client libraries can be called from threads created by the FoundationDB client library. Otherwise, callbacks will be called from either the thread used to add the callback or the network thread. Setting this option can improve performance when connected using an external client, but may not be safe to use in all environments. Must be set before setting up the network. WARNING: This feature is considered experimental at this time
path to cluster file
Disables logging of client statistics, such as sampled transaction activity
Prevents connections through the local client, allowing only connections through externally loaded client libraries. Intended primarily for testing
Disables the multi-version client API and instead uses the local client directly. Must be set before setting up the network
Enables debugging feature to perform slow task profiling. Requires trace logging to be enabled. WARNING: this feature is not recommended for use in production
This option is set automatically on all clients loaded externally using the multi-version API
path to directory containing client libraries
path to client library
Transport ID for the child connection
knob_name=knob_value
IP:PORT
[release version],[source version],[protocol version];
ca bundle
file path
certificates
file path
file path
key passphrase
file path or linker-resolved name
verification pattern
path to output directory (or NULL for current working directory)
value of the logGroup attribute
max total size of trace files
max size of a single trace output file
Infrequently used. The client has passed a specific row limit and wants that many rows delivered in a single batch. Because of iterator operation in client drivers make request batches transparent to the user, consider WANT_ALL
StreamingMode instead. A row limit must be specified if this mode is used
The default. The client doesn’t know how much of the range it is likely to used and wants different performance concerns to be balanced. Only a small portion of data is transferred to the client initially (in order to minimize costs if the client doesn’t read the entire range), and as the caller iterates over more items in the range larger batches will be transferred in order to minimize latency
Infrequently used. Transfer data in batches large enough to be, in a high-concurrency environment, nearly as efficient as possible. If the client stops iteration early, some disk and network bandwidth may be wasted. The batch size may still be too small to allow a single client to get high throughput from the database, so if that is what you need consider the SERIAL StreamingMode
Infrequently used. Transfer data in batches sized in between small and large
Transfer data in batches large enough that an individual client can get reasonable read bandwidth from the database. If the client stops iteration early, considerable disk and network bandwidth may be wasted
Infrequently used. Transfer data in batches small enough to not be much more expensive than reading individual rows, to minimize cost if iteration stops early
Client intends to consume the entire range and would like it all transferred as early as possible
Allows this transaction to read and modify system keys (those that start with the byte 0xFF)
The read version will be committed, and usually will be the latest committed, but might not be the latest committed in the event of a fault or partition
The transaction, if not self-conflicting, may be committed a second time after commit succeeds, in the event of a fault
Committing this transaction will bypass the normal load balancing across proxies and go directly to the specifically nominated ‘first proxy’
Optional transaction name
No other transactions will be applied before this transaction within the same commit version
This is a write-only transaction which sets the initial configuration. This option is designed for use by database system tools only
The transaction can read and write to locked databases, and is resposible for checking that it took the lock
value in milliseconds of maximum delay
The next write performed on this transaction will not generate a write conflict range. As a result, other transactions which read the key(s) being modified by the next write will not conflict with this transaction. Care needs to be taken when using this option on a transaction that is shared between multiple threads. When setting this option, write conflict ranges will be disabled on the next write operation, regardless of what thread it is on
Specifies that this transaction should be treated as low priority and that default priority transactions should be processed first. Useful for doing batch work simultaneously with latency-sensitive work
Specifies that this transaction should be treated as highest priority and that lower priority transactions should block behind this one. Use is discouraged outside of low-level tools
Deprecated
The transaction can read from locked databases
Allows this transaction to read system keys (those that start with the byte 0xFF)
Reads performed by a transaction will not see any prior mutations that occured in that transaction, instead seeing the value which was in the database at the transaction’s read version. This option may provide a small performance benefit for the client, but also disables a number of client-side optimizations which are beneficial for transactions which tend to read and write the same keys within a single transaction
number of times to retry
Snapshot read operations will not see the results of writes done in the same transaction
Snapshot read operations will see the results of writes done in the same transaction
value in milliseconds of timeout
String identifier to be used in the logs when tracing this transaction. The identifier must not exceed 100 characters
By default, operations that are performed on a transaction while it is being committed will not only fail themselves, but they will attempt to fail other in-flight operations (such as the commit) as well. This behavior is intended to help developers discover situations where operations could be unintentionally executed after the transaction has been reset. Setting this option removes that protection, causing only the offending operation to fail
Link to this section Types
Link to this section Functions
Used to add a read conflict range
Used to add a write conflict range
database_option_datacenter_id() :: key()
Hexadecimal ID
Type: String.t/0
Specify the datacenter ID that was passed to fdbserver processes running in the same datacenter as this client, for better location-aware load balancing.
database_option_location_cache_size() :: key()
Max location cache entries
Type: integer/0
Set the size of the client location cache. Raising this value can boost performance in very large databases where clients access data in a near-random pattern. Defaults to 100000.
database_option_machine_id() :: key()
Hexadecimal ID
Type: String.t/0
Specify the machine ID that was passed to fdbserver processes running on the same machine as this client, for better location-aware load balancing.
database_option_max_watches() :: key()
Max outstanding watches
Type: integer/0
Set the maximum number of watches allowed to be outstanding on a database connection. Increasing this number could result in increased resource usage. Reducing this number will not cancel any outstanding watches. Defaults to 10000 and cannot be larger than 1000000.
error_predicate_maybe_committed() :: key()
Returns true
if the error indicates the transaction may have succeeded, though not in a way the system can verify.
Returns true
if the error indicates the operations in the transactions should be retried because of transient error.
error_predicate_retryable_not_committed() :: key()
Returns true
if the error indicates the transaction has not committed, though in a way that can be retried.
addend
Type: binary/0
Performs an addition of little-endian integers. If the existing value in the database is not present or shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
. The integers to be added must be stored in a little-endian representation. They can be signed in two’s complement representation or unsigned. You can add to an integer at a known offset in the value by prepending the appropriate number of zero bytes to param
and padding with zero bytes to match the length of the value. However, this offset technique requires that you know the addition will not cause the integer field within the value to overflow.
value with which to perform bitwise and
Type: binary/0
Deprecated
mutation_type_append_if_fits() :: key()
value to append to the database value
Type: binary/0
Appends param
to the end of the existing value already in the database at the given key (or creates the key and sets the value to param
if the key is empty). This will only append the value if the final concatenated value size is less than or equal to the maximum value size (i.e., if it fits). WARNING: No error is surfaced back to the user if the final value is too large because the mutation will not be applied until after the transaction has been committed. Therefore, it is only safe to use this mutation type if one can guarantee that one will keep the total value size under the maximum size.
value with which to perform bitwise and
Type: binary/0
Performs a bitwise and
operation. If the existing value in the database is not present, then param
is stored in the database. If the existing value in the database is shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
.
value with which to perform bitwise or
Type: binary/0
Performs a bitwise or
operation. If the existing value in the database is not present or shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
.
value with which to perform bitwise xor
Type: binary/0
Performs a bitwise xor
operation. If the existing value in the database is not present or shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
.
value to check against database value
Type: binary/0
Performs lexicographic comparison of byte strings. If the existing value in the database is not present, then param
is stored. Otherwise the larger of the two values is then stored in the database.
value to check against database value
Type: binary/0
Performs lexicographic comparison of byte strings. If the existing value in the database is not present, then param
is stored. Otherwise the smaller of the two values is then stored in the database.
value to check against database value
Type: binary/0
Performs a little-endian comparison of byte strings. If the existing value in the database is not present or shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
. The larger of the two values is then stored in the database.
value to check against database value
Type: binary/0
Performs a little-endian comparison of byte strings. If the existing value in the database is not present, then param
is stored in the database. If the existing value in the database is shorter than param
, it is first extended to the length of param
with zero bytes. If param
is shorter than the existing value in the database, the existing value is truncated to match the length of param
. The smaller of the two values is then stored in the database.
value with which to perform bitwise or
Type: binary/0
Deprecated
mutation_type_set_versionstamped_key() :: key()
value to which to set the transformed key
Type: binary/0
Transforms key
using a versionstamp for the transaction. Sets the transformed key in the database to param
. The key is transformed by removing the final four bytes from the key and reading those as a little-Endian 32-bit integer to get a position pos
. The 10 bytes of the key from pos
to pos + 10
are replaced with the versionstamp of the transaction used. The first byte of the key is position 0. A versionstamp is a 10 byte, unique, monotonically (but not sequentially) increasing value for each committed transaction. The first 8 bytes are the committed version of the database (serialized in big-Endian order). The last 2 bytes are monotonic in the serialization order for transactions. WARNING: At this time, versionstamps are compatible with the Tuple layer only in the Java and Python bindings. Also, note that prior to API version 520, the offset was computed from only the final two bytes rather than the final four bytes.
mutation_type_set_versionstamped_value() :: key()
value to versionstamp and set
Type: binary/0
Transforms param
using a versionstamp for the transaction. Sets the key
given to the transformed param
. The parameter is transformed by removing the final four bytes from param
and reading those as a little-Endian 32-bit integer to get a position pos
. The 10 bytes of the parameter from pos
to pos + 10
are replaced with the versionstamp of the transaction used. The first byte of the parameter is position 0. A versionstamp is a 10 byte, unique, monotonically (but not sequentially) increasing value for each committed transaction. The first 8 bytes are the committed version of the database (serialized in big-Endian order). The last 2 bytes are monotonic in the serialization order for transactions. WARNING: At this time, versionstamps are compatible with the Tuple layer only in the Java and Python bindings. Also, note that prior to API version 520, the versionstamp was always placed at the beginning of the parameter rather than computing an offset.
value with which to perform bitwise xor
Type: binary/0
Deprecated
network_option_buggify_disable() :: key()
network_option_buggify_enable() :: key()
network_option_buggify_section_activated_probability() :: key()
probability expressed as a percentage between 0 and 100
Type: integer/0
Set the probability of a BUGGIFY section being active for the current execution. Only applies to code paths first traversed AFTER this option is changed.
network_option_buggify_section_fired_probability() :: key()
probability expressed as a percentage between 0 and 100
Type: integer/0
Set the probability of an active BUGGIFY section being fired
network_option_callbacks_on_external_threads() :: key()
If set, callbacks from external client libraries can be called from threads created by the FoundationDB client library. Otherwise, callbacks will be called from either the thread used to add the callback or the network thread. Setting this option can improve performance when connected using an external client, but may not be safe to use in all environments. Must be set before setting up the network. WARNING: This feature is considered experimental at this time.
network_option_cluster_file() :: key()
path to cluster file
Type: String.t/0
Deprecated
network_option_disable_client_statistics_logging() :: key()
Disables logging of client statistics, such as sampled transaction activity.
network_option_disable_local_client() :: key()
Prevents connections through the local client, allowing only connections through externally loaded client libraries. Intended primarily for testing.
network_option_disable_multi_version_client_api() :: key()
Disables the multi-version client API and instead uses the local client directly. Must be set before setting up the network.
network_option_enable_slow_task_profiling() :: key()
Enables debugging feature to perform slow task profiling. Requires trace logging to be enabled. WARNING: this feature is not recommended for use in production.
network_option_external_client() :: key()
This option is set automatically on all clients loaded externally using the multi-version API.
network_option_external_client_directory() :: key()
path to directory containing client libraries
Type: String.t/0
Searches the specified path for dynamic libraries and adds them to the list of client libraries for use by the multi-version client API. Must be set before setting up the network.
network_option_external_client_library() :: key()
path to client library
Type: String.t/0
Adds an external client library for use by the multi-version client API. Must be set before setting up the network.
network_option_external_client_transport_id() :: key()
Transport ID for the child connection
Type: integer/0
This option tells a child on a multiversion client what transport ID to use.
knob_name=knob_value
Type: String.t/0
Set internal tuning or debugging knobs
network_option_local_address() :: key()
IP:PORT
Type: String.t/0
Deprecated
network_option_supported_client_versions() :: key()
[release version],[source version],[protocol version];…
Type: String.t/0
This option is set automatically to communicate the list of supported clients to the active client.
network_option_tls_ca_bytes() :: key()
ca bundle
Type: binary/0
Set the ca bundle
network_option_tls_ca_path() :: key()
file path
Type: String.t/0
Set the file from which to load the certificate authority bundle
network_option_tls_cert_bytes() :: key()
certificates
Type: binary/0
Set the certificate chain
network_option_tls_cert_path() :: key()
file path
Type: String.t/0
Set the file from which to load the certificate chain
network_option_tls_key_bytes() :: key()
key
Type: binary/0
Set the private key corresponding to your own certificate
network_option_tls_key_path() :: key()
file path
Type: String.t/0
Set the file from which to load the private key corresponding to your own certificate
network_option_tls_password() :: key()
key passphrase
Type: String.t/0
Set the passphrase for encrypted private key. Password should be set before setting the key for the password to be used.
file path or linker-resolved name
Type: String.t/0
Set the TLS plugin to load. This option, if used, must be set before any other TLS options
network_option_tls_verify_peers() :: key()
verification pattern
Type: binary/0
Set the peer certificate field verification criteria
network_option_trace_enable() :: key()
path to output directory (or NULL for current working directory)
Type: String.t/0
Enables trace output to a file in a directory of the clients choosing
network_option_trace_log_group() :: key()
value of the logGroup attribute
Type: String.t/0
Sets the ‘logGroup’ attribute with the specified value for all events in the trace output files. The default log group is ‘default’.
network_option_trace_max_logs_size() :: key()
max total size of trace files
Type: integer/0
Sets the maximum size of all the trace output files put together. This value should be in the range [0, INT64_MAX]
. If the value is set to 0, there is no limit on the total size of the files. The default is a maximum size of 104,857,600 bytes. If the default roll size is used, this means that a maximum of 10 trace files will be written at a time.
network_option_trace_roll_size() :: key()
max size of a single trace output file
Type: integer/0
Sets the maximum size in bytes of a single trace output file. This value should be in the range [0, INT64_MAX]
. If the value is set to 0, there is no limit on individual file size. The default is a maximum size of 10,485,760 bytes.
Infrequently used. The client has passed a specific row limit and wants that many rows delivered in a single batch. Because of iterator operation in client drivers make request batches transparent to the user, consider WANT_ALL
StreamingMode instead. A row limit must be specified if this mode is used.
The default. The client doesn’t know how much of the range it is likely to used and wants different performance concerns to be balanced. Only a small portion of data is transferred to the client initially (in order to minimize costs if the client doesn’t read the entire range), and as the caller iterates over more items in the range larger batches will be transferred in order to minimize latency.
Infrequently used. Transfer data in batches large enough to be, in a high-concurrency environment, nearly as efficient as possible. If the client stops iteration early, some disk and network bandwidth may be wasted. The batch size may still be too small to allow a single client to get high throughput from the database, so if that is what you need consider the SERIAL StreamingMode.
Infrequently used. Transfer data in batches sized in between small and large.
Transfer data in batches large enough that an individual client can get reasonable read bandwidth from the database. If the client stops iteration early, considerable disk and network bandwidth may be wasted.
Infrequently used. Transfer data in batches small enough to not be much more expensive than reading individual rows, to minimize cost if iteration stops early.
Client intends to consume the entire range and would like it all transferred as early as possible.
transaction_option_access_system_keys() :: key()
Allows this transaction to read and modify system keys (those that start with the byte 0xFF)
transaction_option_causal_read_disable() :: key()
transaction_option_causal_read_risky() :: key()
The read version will be committed, and usually will be the latest committed, but might not be the latest committed in the event of a fault or partition
transaction_option_causal_write_risky() :: key()
The transaction, if not self-conflicting, may be committed a second time after commit succeeds, in the event of a fault
transaction_option_check_writes_enable() :: key()
transaction_option_commit_on_first_proxy() :: key()
Committing this transaction will bypass the normal load balancing across proxies and go directly to the specifically nominated ‘first proxy’.
transaction_option_debug_dump() :: key()
transaction_option_debug_retry_logging() :: key()
Optional transaction name
Type: String.t/0
transaction_option_durability_datacenter() :: key()
transaction_option_durability_dev_null_is_web_scale() :: key()
Deprecated
transaction_option_durability_risky() :: key()
transaction_option_first_in_batch() :: key()
No other transactions will be applied before this transaction within the same commit version.
transaction_option_initialize_new_database() :: key()
This is a write-only transaction which sets the initial configuration. This option is designed for use by database system tools only.
transaction_option_lock_aware() :: key()
The transaction can read and write to locked databases, and is resposible for checking that it took the lock.
transaction_option_max_retry_delay() :: key()
value in milliseconds of maximum delay
Type: integer/0
Set the maximum amount of backoff delay incurred in the call to onError if the error is retryable. Defaults to 1000 ms. Valid parameter values are [0, INT_MAX]
. Like all transaction options, the maximum retry delay must be reset after a call to onError. If the maximum retry delay is less than the current retry delay of the transaction, then the current retry delay will be clamped to the maximum retry delay.
transaction_option_next_write_no_write_conflict_range() :: key()
The next write performed on this transaction will not generate a write conflict range. As a result, other transactions which read the key(s) being modified by the next write will not conflict with this transaction. Care needs to be taken when using this option on a transaction that is shared between multiple threads. When setting this option, write conflict ranges will be disabled on the next write operation, regardless of what thread it is on.
transaction_option_priority_batch() :: key()
Specifies that this transaction should be treated as low priority and that default priority transactions should be processed first. Useful for doing batch work simultaneously with latency-sensitive work
transaction_option_priority_system_immediate() :: key()
Specifies that this transaction should be treated as highest priority and that lower priority transactions should block behind this one. Use is discouraged outside of low-level tools
transaction_option_read_ahead_disable() :: key()
Deprecated
transaction_option_read_lock_aware() :: key()
The transaction can read from locked databases.
transaction_option_read_system_keys() :: key()
Allows this transaction to read system keys (those that start with the byte 0xFF)
transaction_option_read_your_writes_disable() :: key()
Reads performed by a transaction will not see any prior mutations that occured in that transaction, instead seeing the value which was in the database at the transaction’s read version. This option may provide a small performance benefit for the client, but also disables a number of client-side optimizations which are beneficial for transactions which tend to read and write the same keys within a single transaction.
transaction_option_retry_limit() :: key()
number of times to retry
Type: integer/0
Set a maximum number of retries after which additional calls to onError will throw the most recently seen error code. Valid parameter values are [-1, INT_MAX]
. If set to -1, will disable the retry limit. Like all transaction options, the retry limit must be reset after a call to onError. This behavior allows the user to make the retry limit dynamic.
transaction_option_snapshot_ryw_disable() :: key()
Snapshot read operations will not see the results of writes done in the same transaction.
transaction_option_snapshot_ryw_enable() :: key()
Snapshot read operations will see the results of writes done in the same transaction.
transaction_option_timeout() :: key()
value in milliseconds of timeout
Type: integer/0
Set a timeout in milliseconds which, when elapsed, will cause the transaction automatically to be cancelled. Valid parameter values are [0, INT_MAX]
. If set to 0, will disable all timeouts. All pending and any future uses of the transaction will throw an exception. The transaction can be used again after it is reset. Like all transaction options, a timeout must be reset after a call to onError. This behavior allows the user to make the timeout dynamic.
transaction_option_transaction_logging_enable() :: key()
String identifier to be used in the logs when tracing this transaction. The identifier must not exceed 100 characters.
Type: String.t/0
Enables tracing for this transaction and logs results to the client trace logs. Client trace logging must be enabled to get log output.
transaction_option_used_during_commit_protection_disable() :: key()
By default, operations that are performed on a transaction while it is being committed will not only fail themselves, but they will attempt to fail other in-flight operations (such as the commit) as well. This behavior is intended to help developers discover situations where operations could be unintentionally executed after the transaction has been reset. Setting this option removes that protection, causing only the offending operation to fail.