From cd334406afa35f3e1473e742f5800bd9540c55a8 Mon Sep 17 00:00:00 2001 From: Eric Zhao Date: Mon, 28 Jan 2019 16:22:34 +0800 Subject: [PATCH] Code and javadoc refinement Signed-off-by: Eric Zhao --- .../cluster/ClusterErrorMessages.java | 2 +- .../flow/rule/ClusterFlowRuleManager.java | 1 + .../controller/RateLimiterController.java | 11 +++----- .../flow/controller/WarmUpController.java | 25 +++++++++++-------- .../csp/sentinel/slots/logger/LogSlot.java | 4 +-- .../alibaba/csp/sentinel/util/PidUtil.java | 6 +++++ 6 files changed, 28 insertions(+), 21 deletions(-) diff --git a/sentinel-cluster/sentinel-cluster-common-default/src/main/java/com/alibaba/csp/sentinel/cluster/ClusterErrorMessages.java b/sentinel-cluster/sentinel-cluster-common-default/src/main/java/com/alibaba/csp/sentinel/cluster/ClusterErrorMessages.java index 3e6ad416..6b4020a1 100644 --- a/sentinel-cluster/sentinel-cluster-common-default/src/main/java/com/alibaba/csp/sentinel/cluster/ClusterErrorMessages.java +++ b/sentinel-cluster/sentinel-cluster-common-default/src/main/java/com/alibaba/csp/sentinel/cluster/ClusterErrorMessages.java @@ -25,7 +25,7 @@ public final class ClusterErrorMessages { public static final String UNEXPECTED_STATUS = "unexpected status"; public static final String TOO_MANY_REQUESTS = "too many requests (client side)"; public static final String REQUEST_TIME_OUT = "request time out"; - public static final String CLIENT_NOT_READY = "client not ready (not running or initializing)"; + public static final String CLIENT_NOT_READY = "client not ready"; public static final String NO_RULES_IN_SERVER = "no rules in token server"; private ClusterErrorMessages() {} diff --git a/sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/flow/rule/ClusterFlowRuleManager.java b/sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/flow/rule/ClusterFlowRuleManager.java index 13bee56a..85464bb4 100644 --- a/sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/flow/rule/ClusterFlowRuleManager.java +++ b/sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/flow/rule/ClusterFlowRuleManager.java @@ -104,6 +104,7 @@ public final class ClusterFlowRuleManager { } public static void setPropertySupplier(Function>> propertySupplier) { + AssertUtil.notNull(propertySupplier, "flow rule property supplier cannot be null"); ClusterFlowRuleManager.propertySupplier = propertySupplier; } diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/RateLimiterController.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/RateLimiterController.java index 099ff1af..ca07b028 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/RateLimiterController.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/RateLimiterController.java @@ -44,17 +44,12 @@ public class RateLimiterController implements TrafficShapingController { @Override public boolean canPass(Node node, int acquireCount, boolean prioritized) { - /* - 1. Pass when acquire count is less or equal than 0 - 2. Reject when count is less or equal than 0. - Otherwise,the costTime will be max of long and waitTime will overflow in some cases. - This will lead to pass of following request.It's dangerous!!! - */ - + // Pass when acquire count is less or equal than 0. if (acquireCount <= 0) { return true; } - + // Reject when count is less or equal than 0. + // Otherwise,the costTime will be max of long and waitTime will overflow in some cases. if (count <= 0) { return false; } diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/WarmUpController.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/WarmUpController.java index 9e4097f9..a4f69318 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/WarmUpController.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/controller/WarmUpController.java @@ -27,32 +27,37 @@ import com.alibaba.csp.sentinel.slots.block.flow.TrafficShapingController; * rate-based, which means that we need to translate rate to QPS. *

* + *

* Requests arriving at the pulse may drag down long idle systems even though it * has a much larger handling capability in stable period. It usually happens in - * scenarios that require extra time for initialization, e.g. DB - * establishes a connection; connects to a remote service, and so on. - * - * That’s why we need “warm up”. - * - * Sentinel's "warm-up" implementation is based on the guava-based algorithm. - * However, Guava’s implementation focus on adjusting the request interval, in - * other words, a Leaky bucket. Sentinel pays more attention to controlling the - * count of incoming requests per second without calculating its interval, it is - * more like a “Token bucket.” + * scenarios that require extra time for initialization, e.g. DB establishes a connection, + * connects to a remote service, and so on. That’s why we need “warm up”. + *

* + *

+ * Sentinel's "warm-up" implementation is based on the Guava's algorithm. + * However, Guava’s implementation focuses on adjusting the request interval, + * which is similar to leaky bucket. Sentinel pays more attention to + * controlling the count of incoming requests per second without calculating its interval, + * which resembles token bucket algorithm. + *

* + *

* The remaining tokens in the bucket is used to measure the system utility. * Suppose a system can handle b requests per second. Every second b tokens will * be added into the bucket until the bucket is full. And when system processes * a request, it takes a token from the bucket. The more tokens left in the * bucket, the lower the utilization of the system; when the token in the token * bucket is above a certain threshold, we call it in a "saturation" state. + *

* + *

* Base on Guava’s theory, there is a linear equation we can write this in the * form y = m * x + b where y (a.k.a y(x)), or qps(q)), is our expected QPS * given a saturated period (e.g. 3 minutes in), m is the rate of change from * our cold (minimum) rate to our stable (maximum) rate, x (or q) is the * occupied token. + *

* * @author jialiang.linjl */ diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/logger/LogSlot.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/logger/LogSlot.java index b43cd32c..802690a9 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/logger/LogSlot.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/logger/LogSlot.java @@ -38,7 +38,7 @@ public class LogSlot extends AbstractLinkedProcessorSlot { context.getOrigin(), count); throw e; } catch (Throwable e) { - RecordLog.info("Entry exception", e); + RecordLog.warn("Unexpected entry exception", e); } } @@ -48,7 +48,7 @@ public class LogSlot extends AbstractLinkedProcessorSlot { try { fireExit(context, resourceWrapper, count, args); } catch (Throwable e) { - RecordLog.info("Entry exit exception", e); + RecordLog.warn("Unexpected entry exit exception", e); } } } diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/PidUtil.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/PidUtil.java index 31efefb7..720aa285 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/PidUtil.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/util/PidUtil.java @@ -22,7 +22,13 @@ import java.lang.management.ManagementFactory; */ public final class PidUtil { + /** + * Resolve and get current process ID. + * + * @return current process ID + */ public static int getPid() { + // Note: this will trigger local host resolve, which might be slow. String name = ManagementFactory.getRuntimeMXBean().getName(); return Integer.parseInt(name.split("@")[0]); }