SOLR-17481: Resolve use of -n flag in CLI commands

solr/core/src/java/org/apache/solr/cli/RunExampleTool.java

@@ -94,7 +94,7 @@ public String getName() {
   @Override
   public List<Option> getOptions() {
     return List.of(
-        Option.builder("n")
+        Option.builder()
             .longOpt("no-prompt")
             .required(false)
             .desc(

solr/prometheus-exporter/bin/solr-exporter

@@ -116,7 +116,7 @@ if [[ -n "$SCRAPE_INTERVAL" ]]; then
 fi
 
 if [[ -n "$NUM_THREADS" ]]; then
-  EXPORTER_ARGS+=(-n "$NUM_THREADS")
+  EXPORTER_ARGS+=(--num-threads "$NUM_THREADS")
 fi
 
 if [[ -n "$ZK_HOST" ]]; then

solr/prometheus-exporter/bin/solr-exporter.cmd

@@ -79,7 +79,7 @@ set EXPORTER_ARGS=
 IF NOT "%CONFIG_FILE%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% --config-file %CONFIG_FILE%
 IF NOT "%PORT%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% -p %PORT%
 IF NOT "%SCRAPE_INTERVAL%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% --scrape-interval %SCRAPE_INTERVAL%
-IF NOT "%NUM_THREADS%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% -n %NUM_THREADS%
+IF NOT "%NUM_THREADS%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% --num-threads %NUM_THREADS%
 IF NOT "%ZK_HOST%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% -z %ZK_HOST%
 IF NOT "%SOLR_URL%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% -b %SOLR_URL%
 IF NOT "%CLUSTER_ID%"=="" set EXPORTER_ARGS=%EXPORTER_ARGS% -i "%CLUSTER_ID%"

solr/prometheus-exporter/src/java/org/apache/solr/prometheus/exporter/SolrExporter.java

@@ -214,7 +214,7 @@ public static void main(String[] args) {
     mainOptions.addOption(clusterIdOption);
 
     Option numThreadsOption =
-        Option.builder("n")
+        Option.builder()
             .longOpt("num-threads")
             .hasArg()
             .argName("NUM_THREADS")
@@ -225,6 +225,23 @@ public static void main(String[] args) {
                     + ".")
             .build();
     mainOptions.addOption(numThreadsOption);
+    Option numThreadsOptionDeprecated =
+        Option.builder("n")
+            .hasArg()
+            .deprecated(
+                DeprecatedAttributes.builder()
+                    .setForRemoval(true)
+                    .setSince("9.8")
+                    .setDescription("Use --num-threads instead")
+                    .get())
+            .argName("NUM_THREADS")
+            .type(Integer.class)
+            .desc(
+                "Specify the number of threads. solr-exporter creates a thread pools for request to Solr. If you need to improve request latency via solr-exporter, you can increase the number of threads; the default is "
+                    + DEFAULT_NUM_THREADS
+                    + ".")
+            .build();
+    mainOptions.addOption(numThreadsOptionDeprecated);
 
     Option portOption =
         Option.builder("p")
@@ -366,6 +383,12 @@ public static void main(String[] args) {
       } else if (commandLine.hasOption(configOption)) {
         configFile = commandLine.getOptionValue(configOption);
       }
+      int numberOfThreads = DEFAULT_NUM_THREADS;
+      if (commandLine.hasOption("num-threads")) {
+        numberOfThreads = commandLine.getParsedOptionValue("num-threads");
+      } else if (commandLine.hasOption("n")) {
+        numberOfThreads = commandLine.getParsedOptionValue("n");
+      }
 
       int scrapeInterval = DEFAULT_SCRAPE_INTERVAL;
       if (commandLine.hasOption("s")) {
@@ -377,7 +400,7 @@ public static void main(String[] args) {
       SolrExporter solrExporter =
           new SolrExporter(
               port,
-              commandLine.getParsedOptionValue(numThreadsOption, DEFAULT_NUM_THREADS),
+              numberOfThreads,
               scrapeInterval,
               scrapeConfiguration,
               loadMetricsConfiguration(configFile),

solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc

@@ -62,14 +62,14 @@ Linux::
 [source,bash]
 ----
 $ cd prometheus-exporter
-$ ./bin/solr-exporter -p 9854 -b http://localhost:8983/solr --config-file ./conf/solr-exporter-config.xml -n 8
+$ ./bin/solr-exporter -p 9854 -b http://localhost:8983/solr --config-file ./conf/solr-exporter-config.xml --num-threads 8
 ----
 
 .SolrCloud
 [source,bash]
 ----
 $ cd prometheus-exporter
-$ ./bin/solr-exporter -p 9854 -z localhost:2181/solr --config-file ./conf/solr-exporter-config.xml -n 16
+$ ./bin/solr-exporter -p 9854 -z localhost:2181/solr --config-file ./conf/solr-exporter-config.xml --num-threads 16
 ----
 ====
 
@@ -80,14 +80,14 @@ Windows::
 [source,text]
 ----
 > cd prometheus-exporter
-> .\bin\solr-exporter.cmd -p 9854 -b http://localhost:8983/solr --config-file .\conf\solr-exporter-config.xml -n 8
+> .\bin\solr-exporter.cmd -p 9854 -b http://localhost:8983/solr --config-file .\conf\solr-exporter-config.xml --num-threads 8
 ----
 
 .SolrCloud
 [source,text]
 ----
 > cd prometheus-exporter
-> .\bin\solr-exporter -p 9854 -z localhost:2181/solr --config-file .\conf\solr-exporter-config.xml -n 16
+> .\bin\solr-exporter -p 9854 -z localhost:2181/solr --config-file .\conf\solr-exporter-config.xml --num-threads 16
 ----
 ====
 ======
@@ -148,7 +148,7 @@ If neither the `-b` parameter nor the `-z` parameter are defined, the `-b` param
 +
 The path to the configuration file that defines the Solr metrics to read.
 
-`-n`, `--num-threads`, `$NUM_THREADS`::
+`--num-threads`, `$NUM_THREADS`::
 +
 [%autowidth,frame=none]
 |===
@@ -285,7 +285,7 @@ $ cd prometheus-exporter
 $ export JAVA_OPTS="-Djavax.net.ssl.trustStore=truststore.p12 -Djavax.net.ssl.trustStorePassword=truststorePassword -Dsolr.httpclient.builder.factory=org.apache.solr.client.solrj.impl.PreemptiveBasicAuthClientBuilderFactory -Dsolr.httpclient.config=basicauth.properties"
 $ export ZK_CREDS_AND_ACLS="-DzkCredentialsProvider=org.apache.solr.common.cloud.VMParamsSingleSetCredentialsDigestZkCredentialsProvider -DzkDigestUsername=readonly-user -DzkDigestPassword=zkUserPassword"
 $ export CLASSPATH_PREFIX="../server/solr-webapp/webapp/WEB-INF/lib/commons-codec-1.11.jar"
-$ ./bin/solr-exporter -p 9854 -z zk1:2181,zk2:2181,zk3:2181 --config-file ./conf/solr-exporter-config.xml -n 16
+$ ./bin/solr-exporter -p 9854 -z zk1:2181,zk2:2181,zk3:2181 --config-file ./conf/solr-exporter-config.xml --num-threads 16
 ----
 
 NOTE:: The Exporter needs the `commons-codec` library for SSL/BasicAuth, but does not bring it.