librats::StorageConfig Struct Reference

Storage configuration. More...

#include <storage.h>

Collaboration diagram for librats::StorageConfig:

Public Member Functions
	StorageConfig ()

Public Attributes
std::string	data_directory
std::string	database_name
bool	enable_sync
uint32_t	compaction_threshold
uint32_t	max_value_size
bool	persist_to_disk
uint32_t	sync_batch_bytes
	Target payload size of one snapshot chunk.
uint32_t	sync_min_interval_ms
	Minimum gap between two snapshots served to the same peer.

Static Public Attributes
static constexpr uint32_t	kMaxValueSize = 2 * 1024 * 1024
	Ceiling on max_value_size: the default connection low-water mark.
static constexpr uint32_t	kMaxSyncBatchBytes = 2 * 1024 * 1024
	Ceiling on sync_batch_bytes, for the same reason.
static constexpr uint32_t	kMinSyncBatchBytes = 16 * 1024
	Floor on sync_batch_bytes: below this a snapshot costs more in per-message framing and round trips than it saves in queue occupancy.

Detailed Description

Storage configuration.

The two size limits are not free parameters: both are bounded by what one peer's send queue can hold. A connection drops its peer as a slow consumer past its high-water mark (8 MiB by default, NodeConfig::send_queue_limit) and reports "no room" at a quarter of it, so a single value — and a single snapshot chunk — must stay well inside that quarter, or the very first one would kill the link it travels on. Both are clamped to kMaxValueSize / kMaxSyncBatchBytes on construction and in set_config().

Definition at line 188 of file storage.h.

Constructor & Destructor Documentation

StorageConfig()

librats::StorageConfig::StorageConfig ( )

inline

Definition at line 214 of file storage.h.

References compaction_threshold, data_directory, database_name, enable_sync, max_value_size, persist_to_disk, sync_batch_bytes, and sync_min_interval_ms.

Member Data Documentation

compaction_threshold

uint32_t librats::StorageConfig::compaction_threshold

Definition at line 202 of file storage.h.

Referenced by StorageConfig().

data_directory

std::string librats::StorageConfig::data_directory

Definition at line 199 of file storage.h.

Referenced by StorageConfig().

database_name

std::string librats::StorageConfig::database_name

Definition at line 200 of file storage.h.

Referenced by StorageConfig().

enable_sync

bool librats::StorageConfig::enable_sync

Definition at line 201 of file storage.h.

Referenced by StorageConfig().

kMaxSyncBatchBytes

uint32_t librats::StorageConfig::kMaxSyncBatchBytes = 2 * 1024 * 1024

staticconstexpr

Ceiling on sync_batch_bytes, for the same reason.

Definition at line 194 of file storage.h.

kMaxValueSize

uint32_t librats::StorageConfig::kMaxValueSize = 2 * 1024 * 1024

staticconstexpr

Ceiling on max_value_size: the default connection low-water mark.

One value at the ceiling makes a peer unwritable and is then waited out, rather than counting toward the high-water mark that drops it.

Definition at line 192 of file storage.h.

kMinSyncBatchBytes

uint32_t librats::StorageConfig::kMinSyncBatchBytes = 16 * 1024

staticconstexpr

Floor on sync_batch_bytes: below this a snapshot costs more in per-message framing and round trips than it saves in queue occupancy.

Definition at line 197 of file storage.h.

max_value_size

uint32_t librats::StorageConfig::max_value_size

Definition at line 203 of file storage.h.

Referenced by StorageConfig().

persist_to_disk

bool librats::StorageConfig::persist_to_disk

Definition at line 204 of file storage.h.

Referenced by StorageConfig().

sync_batch_bytes

uint32_t librats::StorageConfig::sync_batch_bytes

Target payload size of one snapshot chunk.

The walk stops at the first entry that takes the buffer past this, so a chunk is this size plus at most one entry — which is why max_value_size shares the same ceiling.

Definition at line 208 of file storage.h.

Referenced by StorageConfig().

sync_min_interval_ms

uint32_t librats::StorageConfig::sync_min_interval_ms

Minimum gap between two snapshots served to the same peer.

Bounds what a peer can make us spend by asking, and paces the re-sync a peer is owed after it has been congested.

Definition at line 212 of file storage.h.

Referenced by StorageConfig().

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The documentation for this struct was generated from the following file:

• librats/storage/storage.h