diff --git a/Dockerfile b/Dockerfile
index 0753e38..3322a5c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -19,7 +19,7 @@ RUN Rscript -e "install.packages('pak', repos = sprintf('https://r-lib.github.io
 RUN Rscript -e "pak::pkg_install('rstudio/plumber@main')"
 
 # install required R packages
-RUN Rscript -e "pak::pkg_install(c('logger','tictoc', 'fs', 'promises', 'future'))"
+RUN Rscript -e "pak::pkg_install(c('logger','tictoc', 'fs', 'promises', 'future', 'fastmap'))"
 
 # install testing packages
 RUN Rscript -e "pak::pkg_install(c('testthat', 'httr'))"
diff --git a/helpers/logging.R b/helpers/logging.R
index 4b9fefc..c1ef0dc 100644
--- a/helpers/logging.R
+++ b/helpers/logging.R
@@ -6,10 +6,10 @@ log_dir <- "logs"
 if (!fs::dir_exists(log_dir)) fs::dir_create(log_dir)
 log_appender(appender_tee(tempfile(paste0("plumber_", Sys.time(), "_"), log_dir, ".log")))
 
-convert_empty <- function(string) {
-  if (string == "") {
-    return("-")
-  }
+# transoform empty value to -
+convert_empty <- function(string = "") {
+  if (is.null(string)) return("-")
+  if (string == "") return("-")
   return(string)
 }
 
@@ -19,5 +19,14 @@ pre_route_logging <- function(req) {
 
 post_route_logging <- function(req, res) {
   end <- tictoc::toc(quiet = TRUE) # nolint
-  log_info('{convert_empty(req$REMOTE_ADDR)} "{convert_empty(req$HTTP_USER_AGENT)}" {convert_empty(req$HTTP_HOST)} {convert_empty(req$REQUEST_METHOD)} {convert_empty(end$msg)} {convert_empty(res$status)} {round(end$toc - end$tic, digits = getOption("digits", 5))}') # nolint
+  
+  log_info(sprintf('%s "%s" %s %s %s %s %s', 
+    convert_empty(req$REMOTE_ADDR),
+    convert_empty(req$HTTP_USER_AGENT),
+    convert_empty(req$HTTP_HOST),
+    convert_empty(req$REQUEST_METHOD),
+    convert_empty(end$msg),
+    convert_empty(res$status),
+    round(end$toc - end$tic, digits = getOption("digits", 5))
+  )) # nolint
 }
\ No newline at end of file
diff --git a/helpers/parallel.R b/helpers/parallel.R
index 5d395d4..d6e0073 100644
--- a/helpers/parallel.R
+++ b/helpers/parallel.R
@@ -1,4 +1,5 @@
 library(future)
+library(promises)
 
 future::plan(future::multisession(workers = WORKERS))
 
diff --git a/readme.md b/readme.md
index fa8015a..0d45fdf 100644
--- a/readme.md
+++ b/readme.md
@@ -12,15 +12,15 @@ This repository is a boilerplate to setup a new project with R plumber. You can
 | Dynamic Filter/Miiddleware |     ✅      | Add custom filter / middleware each mounted route from `routes` dir                                                                                                                                             |
 | Request Validation         |     ✅      | Simple validation mechanism to check incoming request from request body / params, such as required fields, check type (number, boolean, array), check the value in given array, etc.                            |
 | Docker                     |     ✅      | Simplifying apps with docker, for better development, deployment, dependencies management, and scaling                                                                                                          |
-| Parallel Processing        |   Not Yet   | R only run a request at a time, make it process in parallel with `promises` and `future` packages.                                                                                                              |
+| Parallel Processing        |     ✅      | R only run a request at a time, make it process in parallel with `promises` and `future` packages.                                                                                                              |
 | Testing                    |     ✅      | Testing for endpoints / routes and helper functions with `testthat` and `httr` packages, also use Docker and docker-compose for setting up automated testing. For running in CI / CD, an example also provided. |
 
 This template comes with built in Environment Variables that you can edit when running it.
 
-| ENV      |   Default   | Description                                                                                    |
-| -------- | :---------: | ---------------------------------------------------------------------------------------------- |
-| `HOST`   | `127.0.0.1` | Host to run Rplumber, use `0.0.0.0` when running it in Docker                                  |
-| `PORT`   |   `8000`    | Which port Rplumber will run                                                                   |
+| ENV       |   Default   | Description                                                                                    |
+| --------- | :---------: | ---------------------------------------------------------------------------------------------- |
+| `HOST`    | `127.0.0.1` | Host to run Rplumber, use `0.0.0.0` when running it in Docker                                  |
+| `PORT`    |   `8000`    | Which port Rplumber will run                                                                   |
 | `WORKERS` |     `3`     | Number of worker (Rsession) to run parallel processing in Rplumber (including the main worker) |
 
 ## How to use it