package com.bazaarvoice.ostrich.dropwizard.healthcheck;
import com.bazaarvoice.ostrich.HealthCheckResult;
import com.bazaarvoice.ostrich.HealthCheckResults;
import com.bazaarvoice.ostrich.ServicePool;
import com.bazaarvoice.ostrich.pool.ServicePoolProxies;
import com.google.common.base.Strings;
import com.yammer.metrics.core.HealthCheck;
import java.util.concurrent.TimeUnit;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
/**
* A simple health check that verifies a pool has a healthy end point. Will perform a health check on at least one end
* point, so beware the possibility of overloading your services with health checks if this is run excessively.
*/
public class ContainsHealthyEndPointCheck extends HealthCheck {
private final ServicePool<?> _pool;
/**
* @deprecated Use {@link #forPool(com.bazaarvoice.ostrich.ServicePool, String)} instead.
*/
public ContainsHealthyEndPointCheck(ServicePool<?> pool, String name) {
super(name);
checkArgument(!Strings.isNullOrEmpty(name));
_pool = checkNotNull(pool);
}
/**
* Returns a newly constructed health check for the given pool that will show as healthy if it has at least one healthy end point.
*
* @param pool The {@code ServicePool} to look for healthy end points in.
* @param name The name of the health check. May not be empty or null.
*/
public static ContainsHealthyEndPointCheck forPool(ServicePool<?> pool, String name) {
return new ContainsHealthyEndPointCheck(pool, name);
}
/**
* Returns a newly constructed health check for the pool of the given proxy that will show as healthy if
* it has at least one healthy end point.
*
* @param proxy The {@code ServicePoolProxy} containing the service pool to look for valid end points in.
* @param name The name of the health check. May not be empty or null.
*/
public static ContainsHealthyEndPointCheck forProxy(Object proxy, String name) {
return new ContainsHealthyEndPointCheck(ServicePoolProxies.getPool(proxy), name);
}
@Override
public Result check() throws Exception {
HealthCheckResults results = _pool.checkForHealthyEndPoint();
boolean healthy = results.hasHealthyResult();
HealthCheckResult healthyResult = results.getHealthyResult();
// Get stats about any failed health checks
int numUnhealthy = 0;
long totalUnhealthyResponseTimeInMicros = 0;
for (HealthCheckResult unhealthy : results.getUnhealthyResults()) {
++numUnhealthy;
totalUnhealthyResponseTimeInMicros += unhealthy.getResponseTime(TimeUnit.MICROSECONDS);
}
if (!healthy && numUnhealthy == 0) {
return Result.unhealthy("No end points.");
}
String unhealthyMessage = numUnhealthy + " failures in " + totalUnhealthyResponseTimeInMicros + "us";
if (!healthy) {
return Result.unhealthy(unhealthyMessage);
}
return Result.healthy(healthyResult.getEndPointId() + " succeeded in " +
healthyResult.getResponseTime(TimeUnit.MICROSECONDS) + "us; " + unhealthyMessage);
}
}