org.rocksdb.RateLimiter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of yamcs-rocksdb Show documentation
Show all versions of yamcs-rocksdb Show documentation
RocksDB fat jar that contains .so files for linux64, jnilib files
for Mac OSX, and a .dll for Windows x64. It contains the Yamcs merge operator for the Parameter Archive
// Copyright (c) 2015, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
package org.rocksdb;
/**
* RateLimiter, which is used to control write rate of flush and
* compaction.
*
* @since 3.10.0
*/
public class RateLimiter extends RocksObject {
public static final long DEFAULT_REFILL_PERIOD_MICROS = 100 * 1000;
public static final int DEFAULT_FAIRNESS = 10;
public static final RateLimiterMode DEFAULT_MODE =
RateLimiterMode.WRITES_ONLY;
public static final boolean DEFAULT_AUTOTUNE = false;
/**
* RateLimiter constructor
*
* @param rateBytesPerSecond this is the only parameter you want to set
* most of the time. It controls the total write rate of compaction
* and flush in bytes per second. Currently, RocksDB does not enforce
* rate limit for anything other than flush and compaction, e.g. write to
* WAL.
*/
public RateLimiter(final long rateBytesPerSecond) {
this(rateBytesPerSecond, DEFAULT_REFILL_PERIOD_MICROS, DEFAULT_FAIRNESS,
DEFAULT_MODE, DEFAULT_AUTOTUNE);
}
/**
* RateLimiter constructor
*
* @param rateBytesPerSecond this is the only parameter you want to set
* most of the time. It controls the total write rate of compaction
* and flush in bytes per second. Currently, RocksDB does not enforce
* rate limit for anything other than flush and compaction, e.g. write to
* WAL.
* @param refillPeriodMicros this controls how often tokens are refilled. For
* example,
* when rate_bytes_per_sec is set to 10MB/s and refill_period_us is set to
* 100ms, then 1MB is refilled every 100ms internally. Larger value can
* lead to burstier writes while smaller value introduces more CPU
* overhead. The default of 100,000ms should work for most cases.
*/
public RateLimiter(final long rateBytesPerSecond,
final long refillPeriodMicros) {
this(rateBytesPerSecond, refillPeriodMicros, DEFAULT_FAIRNESS, DEFAULT_MODE,
DEFAULT_AUTOTUNE);
}
/**
* RateLimiter constructor
*
* @param rateBytesPerSecond this is the only parameter you want to set
* most of the time. It controls the total write rate of compaction
* and flush in bytes per second. Currently, RocksDB does not enforce
* rate limit for anything other than flush and compaction, e.g. write to
* WAL.
* @param refillPeriodMicros this controls how often tokens are refilled. For
* example,
* when rate_bytes_per_sec is set to 10MB/s and refill_period_us is set to
* 100ms, then 1MB is refilled every 100ms internally. Larger value can
* lead to burstier writes while smaller value introduces more CPU
* overhead. The default of 100,000ms should work for most cases.
* @param fairness RateLimiter accepts high-pri requests and low-pri requests.
* A low-pri request is usually blocked in favor of hi-pri request.
* Currently, RocksDB assigns low-pri to request from compaction and
* high-pri to request from flush. Low-pri requests can get blocked if
* flush requests come in continuously. This fairness parameter grants
* low-pri requests permission by fairness chance even though high-pri
* requests exist to avoid starvation.
* You should be good by leaving it at default 10.
*/
public RateLimiter(final long rateBytesPerSecond,
final long refillPeriodMicros, final int fairness) {
this(rateBytesPerSecond, refillPeriodMicros, fairness, DEFAULT_MODE,
DEFAULT_AUTOTUNE);
}
/**
* RateLimiter constructor
*
* @param rateBytesPerSecond this is the only parameter you want to set
* most of the time. It controls the total write rate of compaction
* and flush in bytes per second. Currently, RocksDB does not enforce
* rate limit for anything other than flush and compaction, e.g. write to
* WAL.
* @param refillPeriodMicros this controls how often tokens are refilled. For
* example,
* when rate_bytes_per_sec is set to 10MB/s and refill_period_us is set to
* 100ms, then 1MB is refilled every 100ms internally. Larger value can
* lead to burstier writes while smaller value introduces more CPU
* overhead. The default of 100,000ms should work for most cases.
* @param fairness RateLimiter accepts high-pri requests and low-pri requests.
* A low-pri request is usually blocked in favor of hi-pri request.
* Currently, RocksDB assigns low-pri to request from compaction and
* high-pri to request from flush. Low-pri requests can get blocked if
* flush requests come in continuously. This fairness parameter grants
* low-pri requests permission by fairness chance even though high-pri
* requests exist to avoid starvation.
* You should be good by leaving it at default 10.
* @param rateLimiterMode indicates which types of operations count against
* the limit.
*/
public RateLimiter(final long rateBytesPerSecond,
final long refillPeriodMicros, final int fairness,
final RateLimiterMode rateLimiterMode) {
this(rateBytesPerSecond, refillPeriodMicros, fairness, rateLimiterMode,
DEFAULT_AUTOTUNE);
}
/**
* RateLimiter constructor
*
* @param rateBytesPerSecond this is the only parameter you want to set
* most of the time. It controls the total write rate of compaction
* and flush in bytes per second. Currently, RocksDB does not enforce
* rate limit for anything other than flush and compaction, e.g. write to
* WAL.
* @param refillPeriodMicros this controls how often tokens are refilled. For
* example,
* when rate_bytes_per_sec is set to 10MB/s and refill_period_us is set to
* 100ms, then 1MB is refilled every 100ms internally. Larger value can
* lead to burstier writes while smaller value introduces more CPU
* overhead. The default of 100,000ms should work for most cases.
* @param fairness RateLimiter accepts high-pri requests and low-pri requests.
* A low-pri request is usually blocked in favor of hi-pri request.
* Currently, RocksDB assigns low-pri to request from compaction and
* high-pri to request from flush. Low-pri requests can get blocked if
* flush requests come in continuously. This fairness parameter grants
* low-pri requests permission by fairness chance even though high-pri
* requests exist to avoid starvation.
* You should be good by leaving it at default 10.
* @param rateLimiterMode indicates which types of operations count against
* the limit.
* @param autoTune Enables dynamic adjustment of rate limit within the range
* {@code [rate_bytes_per_sec / 20, rate_bytes_per_sec]}, according to
* the recent demand for background I/O.
*/
public RateLimiter(final long rateBytesPerSecond,
final long refillPeriodMicros, final int fairness,
final RateLimiterMode rateLimiterMode, final boolean autoTune) {
super(newRateLimiterHandle(rateBytesPerSecond,
refillPeriodMicros, fairness, rateLimiterMode.getValue(), autoTune));
}
/**
* This API allows user to dynamically change rate limiter's bytes per second.
* REQUIRED: bytes_per_second > 0
*
* @param bytesPerSecond bytes per second.
*/
public void setBytesPerSecond(final long bytesPerSecond) {
assert(isOwningHandle());
setBytesPerSecond(nativeHandle_, bytesPerSecond);
}
/**
* Returns the bytes per second.
*
* @return bytes per second.
*/
public long getBytesPerSecond() {
assert(isOwningHandle());
return getBytesPerSecond(nativeHandle_);
}
/**
* Request for token to write bytes. If this request can not be satisfied,
* the call is blocked. Caller is responsible to make sure
* {@code bytes < GetSingleBurstBytes()}.
*
* @param bytes requested bytes.
*/
public void request(final long bytes) {
assert(isOwningHandle());
request(nativeHandle_, bytes);
}
/**
* Max bytes can be granted in a single burst.
*
* @return max bytes can be granted in a single burst.
*/
public long getSingleBurstBytes() {
assert(isOwningHandle());
return getSingleBurstBytes(nativeHandle_);
}
/**
* Total bytes that go through rate limiter.
*
* @return total bytes that go through rate limiter.
*/
public long getTotalBytesThrough() {
assert(isOwningHandle());
return getTotalBytesThrough(nativeHandle_);
}
/**
* Total # of requests that go through rate limiter.
*
* @return total # of requests that go through rate limiter.
*/
public long getTotalRequests() {
assert(isOwningHandle());
return getTotalRequests(nativeHandle_);
}
private static native long newRateLimiterHandle(final long rateBytesPerSecond,
final long refillPeriodMicros, final int fairness,
final byte rateLimiterMode, final boolean autoTune);
@Override
protected final void disposeInternal(final long handle) {
disposeInternalJni(handle);
}
private static native void disposeInternalJni(final long handle);
private static native void setBytesPerSecond(final long handle, final long bytesPerSecond);
private static native long getBytesPerSecond(final long handle);
private static native void request(final long handle, final long bytes);
private static native long getSingleBurstBytes(final long handle);
private static native long getTotalBytesThrough(final long handle);
private static native long getTotalRequests(final long handle);
}