Minor changes in readme and error handling

README.md

@@ -37,11 +37,11 @@ While the metrics api associated with performance analyzer provides the last 5 s
 In order to access the batch metrics api, first enable it using one of the following HTTP request:
 
 ```
-POST localhost:9200/_opendistro/performanceanalyzer/batch/config -H ‘Content-Type: application/json’ -d ‘{“enabled”: true}’
-POST localhost:9200/_opendistro/performanceanalyzer/batch/cluster/config -H ‘Content-Type: application/json’ -d ‘{“enabled”: true}’
+POST localhost:9200/_opendistro/performanceanalyzer/batch/config -H ‘Content-Type: application/json’ -d ‘{"enabled": true}’
+POST localhost:9200/_opendistro/performanceanalyzer/batch/cluster/config -H ‘Content-Type: application/json’ -d ‘{"enabled": true}’
 ```
 
-The former enables batch metrics on a single node, while the latter enables it on nodes across the entire cluster. Batch metrics can be disabled using analogous queries with `{“enabled”: false}`.
+The former enables batch metrics on a single node, while the latter enables it on nodes across the entire cluster. Batch metrics can be disabled using analogous queries with `{"enabled": false}`.
 
 You can then query either the config or cluster config apis to see how many minutes worth of batch metrics data will be retained by nodes in the cluster (`batchMetricsRetentionPeriodMinutes`):
 

src/main/java/com/amazon/opendistro/elasticsearch/performanceanalyzer/config/PerformanceAnalyzerController.java

@@ -216,11 +216,12 @@ private void initBatchMetricsStateFromConf() {
             boolean batchMetricsEnabledFromConf;
             try {
                 batchMetricsEnabledFromConf = readBooleanFromFile(filePath);
+            } catch (NoSuchFileException e) {
+                LOG.debug("Error reading Performance Analyzer state from Conf file", e);
+                saveStateToConf(batchMetricsEnabledDefaultValue, BATCH_METRICS_ENABLED_CONF);
+                batchMetricsEnabledFromConf = batchMetricsEnabledDefaultValue;
             } catch (Exception e) {
                 LOG.debug("Error reading Performance Analyzer state from Conf file", e);
-                if (e instanceof NoSuchFileException) {
-                    saveStateToConf(batchMetricsEnabledDefaultValue, BATCH_METRICS_ENABLED_CONF);
-                }
                 batchMetricsEnabledFromConf = batchMetricsEnabledDefaultValue;
             }