Rest Client listener timeout after waiting for [30000] ms

Elastic Stack Elasticsearch
5

I am now pushing half of the data in one request and half of the data in second request. Though I am getting the below exception : listener timeout after waiting for [30000] ms
Below is my code :

try {
		
JSONObject obj = new JSONObject();
		
FileInputStream file = new FileInputStream(new File("C:\\Users\\cajitb\\Desktop\\TempFiles\\op\\TestExcel01.xlsx"));
Workbook workbook = new Workbook(file);
Worksheet worksheet = workbook.getWorksheets().get(0);
Cells cells = worksheet.getCells();
		
		Range range = cells.getMaxDisplayRange();
		int totalColumns = range.getColumnCount();
		int totalRows = range.getRowCount();
		RowCollection rows = cells.getRows();
		int maxColumn = cells.getMaxDataColumn();
		int maxRows = cells.getMaxDataRow();
	
		SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
		Date d1 = new Date();
		System.out.println("Start Time:"+format.format(d1));
		
		List<Object> colList = new ArrayList<Object>();
		String actionMetaData = String.format("{ \"index\" : { \"_index\" : \"%s\", \"_type\" : \"%s\" } }%n", "jsonindex", "jsonindextype");
		for(int i = 0; i<=0 ; i++)
		{
			for (int j = 0; j < totalColumns; j++) 
		    {
				colList.add(cells.get(i, j).getValue());
		    }
		}
		List<String> bulkData = new ArrayList<String>();
		for (int i = 1; i < rows.getCount(); i++) 
		{
		    for (int j = 0; j < totalColumns; j++) 
		    {
		    	String key = (String)colList.get(j); 
		    	if(null==key || "".equals(key))
		    		key = "Column"+j;
		    	obj.put(key, cells.get(i, j).getValue());
		    }
	  
		    Date d = new Date();
		    obj.put("Action_Date", dateFormat.format(d));
		    
		    String jsonString  = obj.toJSONString();
		    bulkData.add(jsonString);
			obj.clear();
		}
		StringBuilder bulkRequestBody = new StringBuilder();
		
		int halfListIndex = 0;
		if(bulkData.size()>30000)
		{
			halfListIndex = bulkData.size()/2;
			
			for(int i=0;i<bulkData.size()/2;i++)
			{
				bulkRequestBody.append(actionMetaData);
			    bulkRequestBody.append(bulkData.get(i));
			    bulkRequestBody.append("\n");
			}
			String jsonString = bulkRequestBody.toString();
			bulkRequestBody.setLength(0);
			HttpEntity entity = new NStringEntity(jsonString, ContentType.APPLICATION_JSON);
			Response indexResponse = restClient.performRequest(
					"PUT",
					"/jsonindex/jsonindextype/_bulk",
					Collections.<String, String>emptyMap(),
					entity);
					
			if(indexResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
			{
				System.out.println("Index Successfully Created");
			}
		}
		
		if(bulkData.size()>30000)
		{
			for(int i = halfListIndex; i<bulkData.size();i++)
			{
				bulkRequestBody.append(actionMetaData);
				bulkRequestBody.append(bulkData.get(i));
				bulkRequestBody.append("\n");
			}
			String jsonString = bulkRequestBody.toString();
			bulkRequestBody.setLength(0);
			HttpEntity entity = new NStringEntity(jsonString, ContentType.APPLICATION_JSON);
			Response indexResponse = restClient.performRequest(
					"PUT",
					"/jsonindex/jsonindextype/_bulk",
					Collections.<String, String>emptyMap(),
					entity);
					//System.out.println(EntityUtils.toString(indexResponse.getEntity()));
			if(indexResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
			{
				System.out.println("Index Successfully Created");
			}
		}
		
		if(bulkData.size()<30000)
		{
			for (String bulkItem : bulkData) {
			    bulkRequestBody.append(actionMetaData);
			    bulkRequestBody.append(bulkItem);
			    bulkRequestBody.append("\n");
			}
			String jsonString = bulkRequestBody.toString();
			bulkRequestBody.setLength(0);
			HttpEntity entity = new NStringEntity(jsonString, ContentType.APPLICATION_JSON);
			Response indexResponse = restClient.performRequest(
					"PUT",
					"/jsonindex/jsonindextype/_bulk",
					Collections.<String, String>emptyMap(),
					entity);
					//System.out.println(EntityUtils.toString(indexResponse.getEntity()));
			if(indexResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
			{
				System.out.println("Index Successfully Created");
			}
			
		}
	 }catch(Exception e)
	{
		 System.out.println("Exception Occure");
		 e.printStackTrace();
	}

I have mentioned my jar versions used. Sometime I am not getting exception like this. Sometime it is giving exception. Please provide me solution. As per your solution I have divided my data to push into elk. Please provide solution.