kvrocks.conf

################################ GENERAL #####################################

# By default kvrocks listens for connections from localhost interface.
# It is possible to listen to just one or multiple interfaces using
# the "bind" configuration directive, followed by one or more IP addresses.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
bind 0.0.0.0

# Unix socket.
#
# Specify the path for the unix socket that will be used to listen for
# incoming connections. There is no default, so kvrocks will not listen
# on a unix socket when not specified.
#
# unixsocket /tmp/kvrocks.sock
# unixsocketperm 777

# Accept connections on the specified port, default is 6666.
port 6666

# Close the connection after a client is idle for N seconds (0 to disable)
timeout 0

# The number of worker's threads, increase or decrease would affect the performance.
workers 8

# By default, kvrocks does not run as a daemon. Use 'yes' if you need it.
# Note that kvrocks will write a PID file in /var/run/kvrocks.pid when daemonized
daemonize no

# Kvrocks implements the cluster solution that is similar to the Redis cluster solution.
# You can get cluster information by CLUSTER NODES|SLOTS|INFO command, it also is
# adapted to redis-cli, redis-benchmark, Redis cluster SDK, and Redis cluster proxy.
# But kvrocks doesn't support communicating with each other, so you must set
# cluster topology by CLUSTER SETNODES|SETNODEID commands, more details: #219.
#
# PLEASE NOTE:
# If you enable cluster, kvrocks will encode key with its slot id calculated by
# CRC16 and modulo 16384, encoding key with its slot id makes it efficient to
# migrate keys based on the slot. So if you enabled at first time, cluster mode must
# not be disabled after restarting, and vice versa. That is to say, data is not
# compatible between standalone mode with cluster mode, you must migrate data
# if you want to change mode, otherwise, kvrocks will make data corrupt.
#
# Default: no

cluster-enabled no


# Persist the cluster nodes topology in local file($dir/nodes.conf). This configuration
# takes effect only if the cluster mode was enabled.
#
# If yes, it will try to load the cluster topology from the local file when starting,
# and dump the cluster nodes into the file if it was changed.
#
# Default: yes
# persist-cluster-nodes-enabled yes

# Set the max number of connected clients at the same time. By default
# this limit is set to 10000 clients. However, if the server is not
# able to configure the process file limit to allow for the specified limit
# the max number of allowed clients is set to the current file limit
#
# Once the limit is reached the server will close all the new connections sending
# an error 'max number of clients reached'.
#
maxclients 10000

# Require clients to issue AUTH <PASSWORD> before processing any other
# commands.  This might be useful in environments in which you do not trust
# others with access to the host running kvrocks.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# Warning: since kvrocks is pretty fast an outside user can try up to
# 150k passwords per second against a good box. This means that you should
# use a very strong password otherwise it will be very easy to break.
#
# requirepass foobared

# If the master is password protected (using the "masterauth" configuration
# directive below) it is possible to tell the slave to authenticate before
# starting the replication synchronization process. Otherwise, the master will
# refuse the slave request.
#
# masterauth foobared

# Master-Salve replication would check db name is matched. if not, the slave should
# refuse to sync the db from master. Don't use the default value, set the db-name to identify
# the cluster.
db-name change.me.db

# The working directory
#
# The DB will be written inside this directory
# Note that you must specify a directory here, not a file name.
dir /tmp/kvrocks

# You can configure where to store your server logs by the log-dir.
# If you don't specify one, we will use the above `dir` as our default log directory.
# We also can send logs to stdout/stderr is as simple as:
#
log-dir stdout

# Log level
# Possible values: info, warning, error, fatal
# Default: info
log-level info

# You can configure log-retention-days to control whether to enable the log cleaner
# and the maximum retention days that the INFO level logs will be kept.
#
# if set to -1, that means to disable the log cleaner.
# if set to 0, all previous INFO level logs will be immediately removed.
# if set to between 0 to INT_MAX, that means it will retent latest N(log-retention-days) day logs.

# By default the log-retention-days is -1.
log-retention-days -1

# When running in daemonize mode, kvrocks writes a PID file in ${CONFIG_DIR}/kvrocks.pid by
# default. You can specify a custom pid file location here.
# pidfile /var/run/kvrocks.pid
pidfile ""

# You can configure a slave instance to accept writes or not. Writing against
# a slave instance may be useful to store some ephemeral data (because data
# written on a slave will be easily deleted after resync with the master) but
# may also cause problems if clients are writing to it because of a
# misconfiguration.
slave-read-only yes

# The slave priority is an integer number published by Kvrocks in the INFO output.
# It is used by Redis Sentinel in order to select a slave to promote into a
# master if the master is no longer working correctly.
#
# A slave with a low priority number is considered better for promotion, so
# for instance if there are three slave with priority 10, 100, 25 Sentinel will
# pick the one with priority 10, that is the lowest.
#
# However a special priority of 0 marks the replica as not able to perform the
# role of master, so a slave with priority of 0 will never be selected by
# Redis Sentinel for promotion.
#
# By default the priority is 100.
slave-priority 100

# TCP listen() backlog.
#
# In high requests-per-second environments you need an high backlog in order
# to avoid slow clients connections issues. Note that the Linux kernel
# will silently truncate it to the value of /proc/sys/net/core/somaxconn so
# make sure to raise both the value of somaxconn and tcp_max_syn_backlog
# in order to Get the desired effect.
tcp-backlog 511

# If the master is an old version, it may have specified replication threads
# that use 'port + 1' as listening port, but in new versions, we don't use
# extra port to implement replication. In order to allow the new replicas to
# copy old masters, you should indicate that the master uses replication port
# or not.
# If yes, that indicates master uses replication port and replicas will connect
# to 'master's listening port + 1' when synchronization.
# If no, that indicates master doesn't use replication port and replicas will
# connect 'master's listening port' when synchronization.
master-use-repl-port no

# Currently, master only checks sequence number when replica asks for PSYNC,
# that is not enough since they may have different replication histories even
# the replica asking sequence is in the range of the master current WAL.
#
# We design 'Replication Sequence ID' PSYNC, we add unique replication id for
# every write batch (the operation of each command on the storage engine), so
# the combination of replication id and sequence is unique for write batch.
# The master can identify whether the replica has the same replication history
# by checking replication id and sequence.
#
# By default, it is not enabled since this stricter check may easily lead to
# full synchronization.
use-rsid-psync no

# Master-Slave replication. Use slaveof to make a kvrocks instance a copy of
# another kvrocks server. A few things to understand ASAP about kvrocks replication.
#
# 1) Kvrocks replication is asynchronous, but you can configure a master to
#    stop accepting writes if it appears to be not connected with at least
#    a given number of slaves.
# 2) Kvrocks slaves are able to perform a partial resynchronization with the
#    master if the replication link is lost for a relatively small amount of
#    time. You may want to configure the replication backlog size (see the next
#    sections of this file) with a sensible value depending on your needs.
# 3) Replication is automatic and does not need user intervention. After a
#    network partition slaves automatically try to reconnect to masters
#    and resynchronize with them.
#
# slaveof <masterip> <masterport>
# slaveof 127.0.0.1 6379

# When a slave loses its connection with the master, or when the replication
# is still in progress, the slave can act in two different ways:
#
# 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
#    still reply to client requests, possibly with out-of-date data, or the
#    data set may just be empty if this is the first synchronization.
#
# 2) if slave-serve-stale-data is set to 'no' the slave will reply with
#    an error "SYNC with master in progress" to all kinds of commands
#    but to INFO and SLAVEOF.
#
slave-serve-stale-data yes

# To guarantee slave's data safe and serve when it is in full synchronization
# state, slave still keep itself data. But this way needs to occupy much disk
# space, so we provide a way to reduce disk occupation, slave will delete itself
# entire database before fetching files from master during full synchronization.
# If you want to enable this way, you can set 'slave-delete-db-before-fullsync'
# to yes, but you must know that database will be lost if master is down during
# full synchronization, unless you have a backup of database.
#
# This option is similar redis replicas RDB diskless load option:
#       repl-diskless-load on-empty-db
#
# Default: no
slave-empty-db-before-fullsync no

# A Kvrocks master is able to list the address and port of the attached
# replicas in different ways. For example the "INFO replication" section
# offers this information, which is used, among other tools, by
# Redis Sentinel in order to discover replica instances.
# Another place where this info is available is in the output of the
# "ROLE" command of a master.
#
# The listed IP address and port normally reported by a replica is
# obtained in the following way:
#
#   IP: The address is auto detected by checking the peer address
#   of the socket used by the replica to connect with the master.
#
#   Port: The port is communicated by the replica during the replication
#   handshake, and is normally the port that the replica is using to
#   listen for connections.
#
# However when port forwarding or Network Address Translation (NAT) is
# used, the replica may actually be reachable via different IP and port
# pairs. The following two options can be used by a replica in order to
# report to its master a specific set of IP and port, so that both INFO
# and ROLE will report those values.
#
# There is no need to use both the options if you need to override just
# the port or the IP address.
#
# replica-announce-ip 5.5.5.5
# replica-announce-port 1234

# If replicas need full synchronization with master, master need to create
# checkpoint for feeding replicas, and replicas also stage a checkpoint of
# the master. If we also keep the backup, it maybe occupy extra disk space.
# You can enable 'purge-backup-on-fullsync' if disk is not sufficient, but
# that may cause remote backup copy failing.
#
# Default: no
purge-backup-on-fullsync no

# The maximum allowed rate (in MB/s) that should be used by replication.
# If the rate exceeds max-replication-mb, replication will slow down.
# Default: 0 (i.e. no limit)
max-replication-mb 0

# The maximum allowed aggregated write rate of flush and compaction (in MB/s).
# If the rate exceeds max-io-mb, io will slow down.
# 0 is no limit
# Default: 500
max-io-mb 500

# The maximum allowed space (in GB) that should be used by RocksDB.
# If the total size of the SST files exceeds max_allowed_space, writes to RocksDB will fail.
# Please see: https://github.com/facebook/rocksdb/wiki/Managing-Disk-Space-Utilization
# Default: 0 (i.e. no limit)
max-db-size 0

# The maximum backup to keep, server cron would run every minutes to check the num of current
# backup, and purge the old backup if exceed the max backup num to keep. If max-backup-to-keep
# is 0, no backup would be kept. But now, we only support 0 or 1.
max-backup-to-keep 1

# The maximum hours to keep the backup. If max-backup-keep-hours is 0, wouldn't purge any backup.
# default: 1 day
max-backup-keep-hours 24

# max-bitmap-to-string-mb use to limit the max size of bitmap to string transformation(MB).
#
# Default: 16
max-bitmap-to-string-mb 16

################################## TLS ###################################

# By default, TLS/SSL is disabled, i.e. `tls-port` is set to 0.
# To enable it, `tls-port` can be used to define TLS-listening ports.
# tls-port 0

# Configure a X.509 certificate and private key to use for authenticating the
# server to connected clients, masters or cluster peers.
# These files should be PEM formatted.
#
# tls-cert-file kvrocks.crt
# tls-key-file kvrocks.key

# If the key file is encrypted using a passphrase, it can be included here
# as well.
#
# tls-key-file-pass secret

# Configure a CA certificate(s) bundle or directory to authenticate TLS/SSL
# clients and peers.  Kvrocks requires an explicit configuration of at least one
# of these, and will not implicitly use the system wide configuration.
#
# tls-ca-cert-file ca.crt
# tls-ca-cert-dir /etc/ssl/certs

# By default, clients on a TLS port are required
# to authenticate using valid client side certificates.
#
# If "no" is specified, client certificates are not required and not accepted.
# If "optional" is specified, client certificates are accepted and must be
# valid if provided, but are not required.
#
# tls-auth-clients no
# tls-auth-clients optional

# By default, only TLSv1.2 and TLSv1.3 are enabled and it is highly recommended
# that older formally deprecated versions are kept disabled to reduce the attack surface.
# You can explicitly specify TLS versions to support.
# Allowed values are case insensitive and include "TLSv1", "TLSv1.1", "TLSv1.2",
# "TLSv1.3" (OpenSSL >= 1.1.1) or any combination.
# To enable only TLSv1.2 and TLSv1.3, use:
#
# tls-protocols "TLSv1.2 TLSv1.3"

# Configure allowed ciphers.  See the ciphers(1ssl) manpage for more information
# about the syntax of this string.
#
# Note: this configuration applies only to <= TLSv1.2.
#
# tls-ciphers DEFAULT:!MEDIUM

# Configure allowed TLSv1.3 ciphersuites.  See the ciphers(1ssl) manpage for more
# information about the syntax of this string, and specifically for TLSv1.3
# ciphersuites.
#
# tls-ciphersuites TLS_CHACHA20_POLY1305_SHA256

# When choosing a cipher, use the server's preference instead of the client
# preference. By default, the server follows the client's preference.
#
# tls-prefer-server-ciphers yes

# By default, TLS session caching is enabled to allow faster and less expensive
# reconnections by clients that support it. Use the following directive to disable
# caching.
#
# tls-session-caching no

# Change the default number of TLS sessions cached. A zero value sets the cache
# to unlimited size. The default size is 20480.
#
# tls-session-cache-size 5000

# Change the default timeout of cached TLS sessions. The default timeout is 300
# seconds.
#
# tls-session-cache-timeout 60

################################## SLOW LOG ###################################

# The Kvrocks Slow Log is a mechanism to log queries that exceeded a specified
# execution time. The execution time does not include the I/O operations
# like talking with the client, sending the reply and so forth,
# but just the time needed to actually execute the command (this is the only
# stage of command execution where the thread is blocked and can not serve
# other requests in the meantime).
#
# You can configure the slow log with two parameters: one tells Kvrocks
# what is the execution time, in microseconds, to exceed in order for the
# command to get logged, and the other parameter is the length of the
# slow log. When a new command is logged the oldest one is removed from the
# queue of logged commands.

# The following time is expressed in microseconds, so 1000000 is equivalent
# to one second. Note that -1 value disables the slow log, while
# a value of zero forces the logging of every command.
slowlog-log-slower-than 100000

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the slow log with SLOWLOG RESET.
slowlog-max-len 128

# If you run kvrocks from upstart or systemd, kvrocks can interact with your
# supervision tree. Options:
#   supervised no      - no supervision interaction
#   supervised upstart - signal upstart by putting kvrocks into SIGSTOP mode
#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
#   supervised auto    - detect upstart or systemd method based on
#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
# Note: these supervision methods only signal "process is ready."
#       They do not enable continuous liveness pings back to your supervisor.
supervised no

################################## PERF LOG ###################################

# The Kvrocks Perf Log is a mechanism to log queries' performance context that
# exceeded a specified execution time. This mechanism uses rocksdb's
# Perf Context and IO Stats Context, Please see:
# https://github.com/facebook/rocksdb/wiki/Perf-Context-and-IO-Stats-Context
#
# This mechanism is enabled when profiling-sample-commands is not empty and
# profiling-sample-ratio greater than 0.
# It is important to note that this mechanism affects performance, but it is
# useful for troubleshooting performance bottlenecks, so it should only be
# enabled when performance problems occur.

# The name of the commands you want to record. Must be original name of
# commands supported by Kvrocks. Use ',' to separate multiple commands and
# use '*' to record all commands supported by Kvrocks.
# Example:
#   - Single command: profiling-sample-commands get
#   - Multiple commands: profiling-sample-commands get,mget,hget
#
# Default: empty
# profiling-sample-commands ""

# Ratio of the samples would be recorded. It is a number between 0 and 100.
# We simply use the rand to determine whether to record the sample or not.
#
# Default: 0
profiling-sample-ratio 0

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the perf log with PERFLOG RESET.
#
# Default: 256
profiling-sample-record-max-len 256

# profiling-sample-record-threshold-ms use to tell the kvrocks when to record.
#
# Default: 100 millisecond
profiling-sample-record-threshold-ms 100

################################## CRON ###################################

# Compact Scheduler, auto compact at schedule time
# time expression format is the same as crontab(currently only support * and int)
# e.g. compact-cron 0 3 * * * 0 4 * * *
# would compact the db at 3am and 4am everyday
# compact-cron 0 3 * * *

# The hour range that compaction checker would be active
# e.g. compaction-checker-range 0-7 means compaction checker would be worker between
# 0-7am every day.
compaction-checker-range 0-7

# When the compaction checker is triggered, the db will periodically pick the SST file
# with the highest "deleted percentage" (i.e. the percentage of deleted keys in the SST 
# file) to compact, in order to free disk space. 
# However, if a specific SST file was created more than "force-compact-file-age" seconds 
# ago, and its percentage of deleted keys is higher than 
# "force-compact-file-min-deleted-percentage", it will be forcely compacted as well.

# Default: 172800 seconds; Range: [60, INT64_MAX];
# force-compact-file-age 172800
# Default: 10 %; Range: [1, 100];
# force-compact-file-min-deleted-percentage 10

# Bgsave scheduler, auto bgsave at scheduled time
# time expression format is the same as crontab(currently only support * and int)
# e.g. bgsave-cron 0 3 * * * 0 4 * * *
# would bgsave the db at 3am and 4am every day

# Command renaming.
#
# It is possible to change the name of dangerous commands in a shared
# environment. For instance, the KEYS command may be renamed into something
# hard to guess so that it will still be available for internal-use tools
# but not available for general clients.
#
# Example:
#
# rename-command KEYS b840fc02d524045429941cc15f59e41cb7be6c52
#
# It is also possible to completely kill a command by renaming it into
# an empty string:
#
# rename-command KEYS ""

################################ MIGRATE #####################################
# If the network bandwidth is completely consumed by the migration task,
# it will affect the availability of kvrocks. To avoid this situation,
# migrate-speed is adopted to limit the migrating speed.
# Migrating speed is limited by controlling the duration between sending data,
# the duration is calculated by: 1000000 * migrate-pipeline-size / migrate-speed (us).
# Value: [0,INT_MAX], 0 means no limit
#
# Default: 4096
migrate-speed 4096

# In order to reduce data transmission times and improve the efficiency of data migration,
# pipeline is adopted to send multiple data at once. Pipeline size can be set by this option.
# Value: [1, INT_MAX], it can't be 0
#
# Default: 16
migrate-pipeline-size 16

# In order to reduce the write forbidden time during migrating slot, we will migrate the incremental
# data several times to reduce the amount of incremental data. Until the quantity of incremental
# data is reduced to a certain threshold, slot will be forbidden write. The threshold is set by
# this option.
# Value: [1, INT_MAX], it can't be 0
#
# Default: 10000
migrate-sequence-gap 10000

################################ ROCKSDB #####################################

# Specify the capacity of metadata column family block cache. A larger block cache
# may make requests faster while more keys would be cached. Max Size is 200*1024.
# Default: 2048MB
rocksdb.metadata_block_cache_size 2048

# Specify the capacity of subkey column family block cache. A larger block cache
# may make requests faster while more keys would be cached. Max Size is 200*1024.
# Default: 2048MB
rocksdb.subkey_block_cache_size 2048

# Metadata column family and subkey column family will share a single block cache
# if set 'yes'. The capacity of shared block cache is
# metadata_block_cache_size + subkey_block_cache_size
#
# Default: yes
rocksdb.share_metadata_and_subkey_block_cache yes

# A global cache for table-level rows in RocksDB. If almost always point
# lookups, enlarging row cache may improve read performance. Otherwise,
# if we enlarge this value, we can lessen metadata/subkey block cache size.
#
# Default: 0 (disabled)
rocksdb.row_cache_size 0

# Number of open files that can be used by the DB.  You may need to
# increase this if your database has a large working set. Value -1 means
# files opened are always kept open. You can estimate number of files based
# on target_file_size_base and target_file_size_multiplier for level-based
# compaction. For universal-style compaction, you can usually set it to -1.
# Default: 4096
rocksdb.max_open_files 8096

# Amount of data to build up in memory (backed by an unsorted log
# on disk) before converting to a sorted on-disk file.
#
# Larger values increase performance, especially during bulk loads.
# Up to max_write_buffer_number write buffers may be held in memory
# at the same time,
# so you may wish to adjust this parameter to control memory usage.
# Also, a larger write buffer will result in a longer recovery time
# the next time the database is opened.
#
# Note that write_buffer_size is enforced per column family.
# See db_write_buffer_size for sharing memory across column families.

# default is 64MB
rocksdb.write_buffer_size 64

# Target file size for compaction, target file size for Leve N can be calculated
# by target_file_size_base * (target_file_size_multiplier ^ (L-1))
#
# Default: 128MB
rocksdb.target_file_size_base 128

# The maximum number of write buffers that are built up in memory.
# The default and the minimum number is 2, so that when 1 write buffer
# is being flushed to storage, new writes can continue to the other
# write buffer.
# If max_write_buffer_number > 3, writing will be slowed down to
# options.delayed_write_rate if we are writing to the last write buffer
# allowed.
rocksdb.max_write_buffer_number 4

# Maximum number of concurrent background jobs (compactions and flushes).
# For backwards compatibility we will set `max_background_jobs =
# max_background_compactions + max_background_flushes` in the case where user
# sets at least one of `max_background_compactions` or `max_background_flushes`
# (we replace -1 by 1 in case one option is unset).
rocksdb.max_background_jobs 4

# DEPRECATED: it is automatically decided based on the value of rocksdb.max_background_jobs
# Maximum number of concurrent background compaction jobs, submitted to
# the default LOW priority thread pool.
rocksdb.max_background_compactions -1

# DEPRECATED: it is automatically decided based on the value of rocksdb.max_background_jobs
# Maximum number of concurrent background memtable flush jobs, submitted by
# default to the HIGH priority thread pool. If the HIGH priority thread pool
# is configured to have zero threads, flush jobs will share the LOW priority
# thread pool with compaction jobs.
rocksdb.max_background_flushes -1

# This value represents the maximum number of threads that will
# concurrently perform a compaction job by breaking it into multiple,
# smaller ones that are run simultaneously.
# Default: 2 (i.e. no subcompactions)
rocksdb.max_sub_compactions 2

# In order to limit the size of WALs, RocksDB uses DBOptions::max_total_wal_size
# as the trigger of column family flush. Once WALs exceed this size, RocksDB
# will start forcing the flush of column families to allow deletion of some
# oldest WALs. This config can be useful when column families are updated at
# non-uniform frequencies. If there's no size limit, users may need to keep
# really old WALs when the infrequently-updated column families hasn't flushed
# for a while.
#
# In kvrocks, we use multiple column families to store metadata, subkeys, etc.
# If users always use string type, but use list, hash and other complex data types
# infrequently, there will be a lot of old WALs if we don't set size limit
# (0 by default in rocksdb), because rocksdb will dynamically choose the WAL size
# limit to be [sum of all write_buffer_size * max_write_buffer_number] * 4 if set to 0.
#
# Moreover, you should increase this value if you already set rocksdb.write_buffer_size
# to a big value, to avoid influencing the effect of rocksdb.write_buffer_size and
# rocksdb.max_write_buffer_number.
#
# default is 512MB
rocksdb.max_total_wal_size 512

# We implement the replication with rocksdb WAL, it would trigger full sync when the seq was out of range.
# wal_ttl_seconds and wal_size_limit_mb would affect how archived logs will be deleted.
# If WAL_ttl_seconds is not 0, then WAL files will be checked every WAL_ttl_seconds / 2 and those that
# are older than WAL_ttl_seconds will be deleted#
#
# Default: 3 Hours
rocksdb.wal_ttl_seconds 10800

# If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0,
# WAL files will be checked every 10 min and if total size is greater
# then WAL_size_limit_MB, they will be deleted starting with the
# earliest until size_limit is met. All empty files will be deleted
# Default: 16GB
rocksdb.wal_size_limit_mb 16384

# Approximate size of user data packed per block.  Note that the
# block size specified here corresponds to uncompressed data. The
# actual size of the unit read from disk may be smaller if
# compression is enabled.
#
# Default: 4KB
rocksdb.block_size 16384

# Indicating if we'd put index/filter blocks to the block cache
#
# Default: no
rocksdb.cache_index_and_filter_blocks yes

# Specify the compression to use. Only compress level greater
# than 2 to improve performance.
# Accept value: "no", "snappy", "lz4", "zstd", "zlib"
# default snappy
rocksdb.compression snappy

# If non-zero, we perform bigger reads when doing compaction. If you're
# running RocksDB on spinning disks, you should set this to at least 2MB.
# That way RocksDB's compaction is doing sequential instead of random reads.
# When non-zero, we also force new_table_reader_for_compaction_inputs to
# true.
#
# Default: 2 MB
rocksdb.compaction_readahead_size 2097152

# he limited write rate to DB if soft_pending_compaction_bytes_limit or
# level0_slowdown_writes_trigger is triggered.

# If the value is 0, we will infer a value from `rater_limiter` value
# if it is not empty, or 16MB if `rater_limiter` is empty. Note that
# if users change the rate in `rate_limiter` after DB is opened,
# `delayed_write_rate` won't be adjusted.
#
rocksdb.delayed_write_rate 0
# If enable_pipelined_write is true, separate write thread queue is
#  maintained for WAL write and memtable write.
#
#  Default: no
rocksdb.enable_pipelined_write no

# Soft limit on number of level-0 files. We start slowing down writes at this
#  point. A value <0 means that no writing slow down will be triggered by
# number of files in level-0.
#
# Default: 20
rocksdb.level0_slowdown_writes_trigger 20

# Maximum number of level-0 files.  We stop writes at this point.
#
# Default: 40
rocksdb.level0_stop_writes_trigger 40

# Number of files to trigger level-0 compaction.
#
# Default: 4
rocksdb.level0_file_num_compaction_trigger 4

# if not zero, dump rocksdb.stats to LOG every stats_dump_period_sec
#
# Default: 0
rocksdb.stats_dump_period_sec 0

# if yes, the auto compaction would be disabled, but the manual compaction remain works
#
# Default: no
rocksdb.disable_auto_compactions no

# BlobDB(key-value separation) is essentially RocksDB for large-value use cases.
# Since 6.18.0, The new implementation is integrated into the RocksDB core.
# When set, large values (blobs) are written to separate blob files, and only
# pointers to them are stored in SST files. This can reduce write amplification
# for large-value use cases at the cost of introducing a level of indirection
# for reads. Please see: https://github.com/facebook/rocksdb/wiki/BlobDB.
#
# Note that when enable_blob_files is set to yes, BlobDB-related configuration
# items will take effect.
#
# Default: no
rocksdb.enable_blob_files no

# The size of the smallest value to be stored separately in a blob file. Values
# which have an uncompressed size smaller than this threshold are stored alongside
# the keys in SST files in the usual fashion.
#
# Default: 4096 byte, 0 means that all values are stored in blob files
rocksdb.min_blob_size 4096

# The size limit for blob files. When writing blob files, a new file is
# opened once this limit is reached.
#
# Default: 268435456 bytes
rocksdb.blob_file_size 268435456

# Enables garbage collection of blobs. Valid blobs residing in blob files
# older than a cutoff get relocated to new files as they are encountered
# during compaction, which makes it possible to clean up blob files once
# they contain nothing but obsolete/garbage blobs.
# See also rocksdb.blob_garbage_collection_age_cutoff below.
#
# Default: yes
rocksdb.enable_blob_garbage_collection yes

# The percentage cutoff in terms of blob file age for garbage collection.
# Blobs in the oldest N blob files will be relocated when encountered during
# compaction, where N = (garbage_collection_cutoff/100) * number_of_blob_files.
# Note that this value must belong to [0, 100].
#
# Default: 25
rocksdb.blob_garbage_collection_age_cutoff 25


# The purpose of the following three options are to dynamically adjust the upper limit of
# the data that each layer can store according to the size of the different
# layers of the LSM. Enabling this option will bring some improvements in
# deletion efficiency and space amplification, but it will lose a certain
# amount of read performance.
# If you want to know more details about Levels' Target Size, you can read RocksDB wiki:
# https://github.com/facebook/rocksdb/wiki/Leveled-Compaction#levels-target-size
#
# Default: no
rocksdb.level_compaction_dynamic_level_bytes no

# The total file size of level-1 sst.
#
# Default: 268435456 bytes
rocksdb.max_bytes_for_level_base 268435456

# Multiplication factor for the total file size of L(n+1) layers.
# This option is a double type number in RocksDB, but kvrocks is
# not support the double data type number yet, so we use integer
# number instead of double currently.
#
# Default: 10
rocksdb.max_bytes_for_level_multiplier 10

# This feature only takes effect in Iterators and MultiGet.
# If yes, RocksDB will try to read asynchronously and in parallel as much as possible to hide IO latency.
# In iterators, it will prefetch data asynchronously in the background for each file being iterated on. 
# In MultiGet, it will read the necessary data blocks from those files in parallel as much as possible.

# Default no
rocksdb.read_options.async_io no

# If yes, the write will be flushed from the operating system
# buffer cache before the write is considered complete.
# If this flag is enabled, writes will be slower.
# If this flag is disabled, and the machine crashes, some recent
# rites may be lost.  Note that if it is just the process that
# crashes (i.e., the machine does not reboot), no writes will be
# lost even if sync==false.
#
# Default: no
rocksdb.write_options.sync no

# If yes, writes will not first go to the write ahead log,
# and the write may get lost after a crash.
#
# Deafult: no
rocksdb.write_options.disable_wal no

# If enabled and we need to wait or sleep for the write request, fails
# immediately.
#
# Default: no
rocksdb.write_options.no_slowdown no

# If enabled, write requests are of lower priority if compaction is
# behind. In this case, no_slowdown = true, the request will be canceled
# immediately. Otherwise, it will be slowed down.
# The slowdown value is determined by RocksDB to guarantee
# it introduces minimum impacts to high priority writes.
#
# Default: no
rocksdb.write_options.low_pri no

# If enabled, this writebatch will maintain the last insert positions of each
# memtable as hints in concurrent write. It can improve write performance
# in concurrent writes if keys in one writebatch are sequential.
#
# Default: no
rocksdb.write_options.memtable_insert_hint_per_batch no

################################ NAMESPACE #####################################
# namespace.test change.me