Mastering Eureka: 100+ Essential Configuration Parameters Explained

Eureka Client Configuration

RegistryFetchIntervalSeconds : Interval (seconds) to fetch registry info from Eureka server, default 30.

InstanceInfoReplicationIntervalSeconds : Interval (seconds) to replicate instance changes to server, default 30.

InitialInstanceInfoReplicationIntervalSeconds : Initial replication interval (seconds), default 40.

EurekaServiceUrlPollIntervalSeconds : Interval (seconds) to poll Eureka service URL changes, default 300.

ProxyHost : Proxy host for Eureka service, default null.

ProxyPort : Proxy port for Eureka service, default null.

ProxyUserName : Proxy username, default null.

ProxyPassword : Proxy password, default null.

GZipContent : Whether registry content is gzipped, default true.

EurekaServerReadTimeoutSeconds : Read timeout (seconds) for server, default 8.

EurekaServerConnectTimeoutSeconds : Connect timeout (seconds) for server, default 5.

BackupRegistryImpl : Implementation class name for backup registry, default null.

EurekaServerTotalConnections : Max total connections to Eureka servers, default 200.

EurekaServerTotalConnectionsPerHost : Max connections per host, default 50.

EurekaServerURLContext : Context path for Eureka (e.g., /eureka), default null.

EurekaServerPort : Port for Eureka server when using DNS, default null.

EurekaServerDNSName : DNS name to resolve Eureka servers, default null.

UseDnsForFetchingServiceUrls : Use DNS to fetch service URLs, default false.

RegisterWithEureka : Register instance with Eureka, default true.

PreferSameZoneEureka : Prefer servers in the same zone, default true.

AllowRedirects : Allow server redirects, default false.

LogDeltaDiff : Log registry delta differences, default false.

DisableDelta : Disable delta replication, default false.

fetchRegistryForRemoteRegions : Comma‑separated list of remote regions, default null.

Region : Instance region, default us-east-1.

AvailabilityZones : Comma‑separated list of availability zones.

EurekaServerServiceUrls : URLs of Eureka servers, default http:// host : port /eureka/.

FilterOnlyUpInstances : Return only up instances, default true.

EurekaConnectionIdleTimeoutSeconds : Idle timeout for HTTP connections, default 30.

FetchRegistry : Whether to fetch registry, default true.

RegistryRefreshSingleVipAddress : Refresh a single VIP address, default null.

HeartbeatExecutorThreadPoolSize : Heartbeat thread pool size, default 5.

HeartbeatExecutorExponentialBackOffBound : Heartbeat back‑off multiplier, default 10.

CacheRefreshExecutorThreadPoolSize : Cache refresh thread pool size, default 5.

CacheRefreshExecutorExponentialBackOffBound : Cache refresh back‑off multiplier, default 10.

DollarReplacement : Replacement for "$" in serialization, default "_-".

EscapeCharReplacement : Replacement for escape character, default "_".

OnDemandUpdateStatusChange : On‑demand status updates, default true.

EncoderName : Encoder class name, default null.

DecoderName : Decoder class name, default null.

ClientDataAccept : Client data acceptance flag.

Experimental : Experimental features flag, default null.

Instance Microservice Configuration

InstanceId : Unique ID for the instance (e.g., ${spring.application.name}:${spring.application.instance_id:${random.value}}).

Appname : Application name registered in Eureka, default "unknown".

AppGroupName : Application group name, default "unknown".

InstanceEnabledOnit : Whether the instance is enabled on start, default false.

NonSecurePort : Non‑secure port, default 80.

SecurePort : Secure port, default 443.

NonSecurePortEnabled : Enable non‑secure port, default true.

SecurePortEnabled : Enable secure port, default false.

LeaseRenewalIntervalInSeconds : Heartbeat interval to Eureka, default 30.

LeaseExpirationDurationInSeconds : Time after last heartbeat before instance is removed, default 90.

VirtualHostName : Virtual host name for the instance.

SecureVirtualHostName : Secure virtual host name.

ASGName : AWS Auto Scaling Group name, used in AWS environments.

HostName : Host name of the instance.

MetadataMap : Key‑value metadata sent to Eureka.

DataCenterInfo : Data‑center information.

IpAddress : IP address of the instance.

StatusPageUrlPath : Path of the status page, default "/info".

StatusPageUrl : Absolute URL of the status page, default null.

HomePageUrlPath : Path of the home page, default "/".

HomePageUrl : Absolute home page URL, default null.

HealthCheckUrlPath : Path of the health‑check endpoint, default "/health".

HealthCheckUrl : Absolute health‑check URL, default null.

SecureHealthCheckUrl : Secure health‑check URL, default null.

DefaultAddressResolutionOrder : Address resolution order, default [].

Namespace : Namespace for property lookup, default "eureka".

Eureka Server Configuration

AWSAccessId : AWS access ID for elastic IP binding, default null.

AWSSecretKey : AWS secret key, default null.

EIPBindRebindRetries : Retries for binding EIP, default 3.

EIPBindingRetryIntervalMsWhenUnbound : Interval (ms) to retry EIP binding when unbound, default 1601000.

EIPBindingRetryIntervalMs : Interval (ms) for stable EIP binding checks, default 5601000.

EnableSelfPreservation : Enable self‑preservation mode, default true.

RenewalPercentThreshold : Threshold factor for self‑preservation, default 0.85.

RenewalThresholdUpdateIntervalMs : Interval (ms) to update renewal threshold, default 1560000.

PeerEurekaNodesUpdateIntervalMs : Interval (ms) to update peer node info, default 1060000.

EnableReplicatedRequestCompression : Compress replicated requests, default false.

NumberOfReplicationRetries : Retry count for replication, default 5.

PeerEurekaStatusRefreshTimeIntervalMs : Interval (ms) to refresh peer status, default 30000.

WaitTimeInMsWhenSyncEmpty : Wait time (ms) when sync finds no data, default 1000605.

PeerNodeConnectTimeoutMs : Connect timeout (ms) for peer nodes, default 200.

PeerNodeReadTimeoutMs : Read timeout (ms) for peer nodes, default 200.

PeerNodeTotalConnections : Max total connections to peer nodes, default 1000.

PeerNodeTotalConnectionsPerHost : Max connections per host, default 500.

PeerNodeConnectionIdleTimeoutSeconds : Idle timeout (seconds) for peer connections, default 30.

RetentionTimeInMSInDeltaQueue : Retention time (ms) for delta queue, default 3600000.

DeltaRetentionTimerIntervalInMs : Interval (ms) for delta cleanup, default 30000.

EvictionIntervalTimerInMs : Interval (ms) for eviction tasks, default 60000.

ASGQueryTimeoutMs : Timeout (ms) for ASG queries, default 300.

ASGUpdateIntervalMs : Interval (ms) to update ASG info, default 5600000.

ASGCacheExpiryTimeoutMs : Cache expiry (ms) for ASG info, default 1060000.

ResponseCacheAutoExpirationInSeconds : Cache auto‑expiration (seconds) after registry change, default 180.

ResponseCacheUpdateIntervalMs : Interval (ms) to update response cache, default 30000.

UseReadOnlyResponseCache : Use read‑only cache, default true.

DisableDelta : Disable delta replication to clients, default false.

MaxIdleThreadInMinutesAgeForStatusReplication : Max idle time (minutes) for status replication threads, default 10.

MinThreadsForStatusReplication : Minimum threads for status replication, default 1.

MaxThreadsForStatusReplication : Maximum threads for status replication, default 1.

MaxElementsInStatusReplicationPool : Max elements in status replication pool, default 10000.

SyncWhenTimestampDiffers : Sync when timestamps differ, default true.

RegistrySyncRetries : Retries for registry sync at startup, default 5.

RegistrySyncRetryWaitMs : Wait (ms) between sync retries, default 30000.

MaxElementsInPeerReplicationPool : Max elements in peer replication pool, default 10000.

MaxIdleThreadAgeInMinutesForPeerReplication : Max idle minutes for peer replication threads, default 15.

MinThreadsForPeerReplication : Minimum peer replication threads, default 5.

MaxThreadsForPeerReplication : Maximum peer replication threads, default 20.

MaxTimeForReplication : Max time (ms) before discarding a replication event, default 30000.

PrimeAwsReplicaConnections : Prime AWS replica connections, default true.

DisableDeltaForRemoteRegions : Disable delta for remote regions, default false.

RemoteRegionConnectTimeoutMs : Connect timeout (ms) for remote regions, default 1000.

RemoteRegionReadTimeoutMs : Read timeout (ms) for remote regions, default 1000.

RemoteRegionTotalConnections : Total connections for remote regions, default 1000.

RemoteRegionTotalConnectionsPerHost : Connections per host for remote regions, default 500.

RemoteRegionConnectionIdleTimeoutSeconds : Idle timeout (seconds) for remote region connections, default 30.

GZipContentFromRemoteRegion : Gzip content from remote regions, default true.

RemoteRegionUrlsWithName : Map of remote region URLs with names.

RemoteRegionUrls : List of remote region URLs.

RemoteRegionAppWhitelist : Whitelisted apps for remote regions.

RemoteRegionRegistryFetchInterval : Fetch interval (seconds) for remote registry, default 30.

RemoteRegionFetchThreadPoolSize : Thread pool size for remote fetch, default 20.

RemoteRegionTrustStore : Trust store for remote region requests, default empty.

RemoteRegionTrustStorePassword : Trust store password, default "changeit".

disableTransparentFallbackToOtherRegion : Disable transparent fallback, default false.

BatchReplication : Enable batch replication, default false.

LogIdentityHeaders : Log client authentication headers, default true.

RateLimiterEnabled : Enable rate limiting, default false.

RateLimiterThrottleStandardClients : Throttle standard clients, default false.

RateLimiterPrivilegedClients : List of privileged clients.

RateLimiterBurstSize : Burst size for token‑bucket limiter, default 10.

RateLimiterRegistryFetchAverageRate : Average registry fetch rate, default 500.

RateLimiterFullFetchAverageRate : Average full fetch rate, default 100.

ListAutoScalingGroupsRoleName : Role name for listing AWS auto‑scaling groups, default "ListAutoScalingGroups".

JsonCodecName : JSON codec class name, default null.

XmlCodecName : XML codec class name, default null.

BindingStrategy : Strategy for binding EIP or Route53.

Route53DomainTTL : TTL for Route53 domain, default 301.

Route53BindRebindRetries : Retries for binding Route53 domain, default 3.

Route53BindingRetryIntervalMs : Interval (ms) for Route53 binding retries, default 5601000.

Experimental : Experimental feature flag, default null.

The article concludes that most of these parameters have sensible defaults and only a subset need to be customized based on specific business requirements.