Solr is a popular, open source enterprise search platform built on Apache Lucene. Providing distributed search and index replication, Solr is designed for scalability and Fault tolerance. With load-balanced querying, automated failover and recovery, Solr drives the search and navigation features of many of the world's largest internet sites.
Let’s take a look at what you need to see to monitor Solr, the performance metrics to gather and how you can ensure that your Solr search server is up and operating as expected with Applications Manager:
Supported versions : Apache Solr 7.5 and lower versions.
Using the REST API to add a new Apache Solr monitor: Click here
To create an Apache Solr Monitor, follow the steps given below:
Go to the Monitors Category View by clicking the Monitors tab. Click on Apache Solr under the Web Server/Services Table. Displayed is the Apache Solr bulk configuration view distributed into three tabs:
Click on the monitor name to see all the server details listed under the following tabs:
| Parameter | Description |
|---|---|
| Core Details | |
| Total number of cores | The total number of Solr cores on a single Solr instance. (A Solr core is an index and associated transaction log and configuration files. An installation can have multiple cores.) |
| Active cores | The total number of active Solr cores, i.e a core that is in active state for querying, on the Solr instance. |
| Lead Cores | The total number of active leader Solr cores. |
| Cores | |
| Core Name | The name of the Solr core on the instance. |
| Host Name | The host name of the machine running Solr. |
| Number of Docs / Min | The number of documents added into a collection per minute. |
| Max Docs / Min | The maximum number of documents that can be added to a collection per minute. |
| Deleted Docs / Min | The number of documents deleted from the collection per minute. |
| State | The state of corresponding core, whether it is active or inactive. This is referred in turn for querying. |
| Searcher Warmup Time | The warmup time taken by searcher in between the query processing. |
| Average Search Time | The average time taken for processing the query and searching. |
| Replication | |
| Core Name | The name of the Solr core on the instance. |
| Master Node | Specifies if a replication instance of Solr is a master. |
| Slave Node | Specifies if a replication instance of Solr is a slave. |
| Index Size | Specifies the index size of the individual cores. |
| Replications Enabled | Specifies if you have master/slave replication enabled. |
| Parameter | Description |
|---|---|
| Thread Details | |
| WAITING Threads | Thread State - A thread that is waiting indefinitely for another thread to perform a particular action. |
| TIMED_WAITING Threads | Thread State - A thread that is waiting for another thread to perform an action for up to a specified waiting time. |
| RUNNABLE Threads | Thread State - A thread executing in the Java virtual machine. |
| BLOCKED Threads | Thread State - A thread that is blocked waiting for a monitor lock. |
| TERMINATED Threads | Thread State - A thread that has exited. |
| Memory Usage | |
| Core Name | The name of the Solr core on the instance. |
| Used Memory (MB) | The space that is currently occupied. |
| Free Memory (MB) | The total free memory available to the JVM. |
| Committed Virtual Memory Size (MB) | The total size of virtual memory that is currently occupied by the corresponding Solr cores. |
| Free Physical Memory Size (MB) | The total size of physical memory that is free and available for the Solr cores. |
| Free Swap Space Size (MB) | The total size of the swap space that is free and available for swapping when the virtual memory reaches the limit. |
| ProcessCPUTime (sec) | The total CPU time taken by the corresponding Solr cores, for executing the instructions. |
| Used Memory (%) | The percentage of space that is currently occupied. |
| Free Memory (%) | The percentage of free memory available to the JVM. |
| Memory Utilization | |
| Total Physical Memory Size | The total size of physical memory that is available for the Solr for its operations and storage. |
| Total Swap Space Size | The total size of the swap space that is available for swapping when the virtual memory reaches the limit. |
| Total Heap Memory | The total heap memory available for the Solr instance. |
| Max Heap Memory | The maximum heap memory that the Solr instance can use. |
| Parameter | Description |
|---|---|
| Query Handler | |
| Core Name | The name of the Solr core on the instance. |
| Search Requests / Min | The total search requests handled by the corresponding Solr cores per minute. |
| Search Errors / Min | The total errors that occur during the search requests handled by the corresponding Solr cores per minute. |
| Search Timeouts / Min | The total timeouts that occur during the search requests handled by the corresponding Solr cores per minute. |
| Average Search Time | The average time taken for handling the each search requests handled by the corresponding Solr cores per minute. |
| Replication Requests / Min | The total replication requests handled by the corresponding Solr cores per minute. |
| Update Requests / Min | The total update requests handled by the corresponding Solr cores per minute. |
| Luke Requests / Min | The total Luke requests handled by the corresponding Solr cores per minute. |
| Cache | |
| Core Name | The name of the Solr core on the instance. |
| Cache Name | The name of your application cache. |
| Lookups / Min | Number of Solr query cache lookups per minute. |
| Hits / Min | Number of query hits per minute. |
| Hit Ratio / Min | The percentage of requests that are satisfied by entries already in the cache per minute. |
| Evictions / Min | The number of entries removed from the cache per minute. |
| Cache Size (Bytes) | The size of the field value cache. |
| Update Handler | |
| Core Name | The name of the Solr core on the instance. |
| Commits / Min | The number of commits per minute. (A commit writes all loaded documents to one or more segment files on the disk.) |
| Rollbacks / Min | The number of rollbacks per minute. (The rollback reverts all add and deletes made to the index since the last commit.) |
| Docs Add / Min | The number of documents added per minute. |
| Docs Deleted by Query / Min | The number of documents deleted by Query per minute. |
| Docs Deleted by ID / Min | The number of documents deleted by ID per minute. |
| Docs Pending | The number of documents pending commit. |
| Errors / Min | The number of errors occurred per minute. |
| Optimizations / Min | The number of optimizations done per minute. |
| Number of Transaction Logs | The total number of the transaction logs. |
| Transaction Logs size (Bytes) | The total size of the transaction logs. |
| Parameter | Description |
|---|---|
| OS Name | The name of the operating system used in the running machine. |
| Architecture | The architecture of the machine where the instance is running. |
| Available Processors | The total available processors of the machine where the instance is running. |
| Java Installation Directory | The home directory where the java instance used by Apache Solr is installed on the machine. |
| Java Version | The version of the java instance used by Apache Solr installed in the machine. |
| Java Vendor | The vendor of the Java instance used by Apache Solr installed in the machine. |
| Jetty Home | The home directory where the jetty server is installed in the machine. |
| Controller Port | The port where the jetty server is currently running in the machine. |
| Client Name | The current machine name. |
| User Directory | The home directory where the Solr is installed. |
| Solr Version | The version of the Solr installed. |
| Lucene Version | The version of the Lucene installed. |
| Deployment Mode | The current deployment mode of the Solr (Cloud or Standalone). |
| Cluster Client TimeOut | The maximum timeout set for the connection establishment with zookeeper. |
