diff --git a/.gitignore b/.gitignore
index e5528b08..5d528d38 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,6 +19,7 @@ __debug_bin
 .idea/
 __pycache__
 .DS_Store
+*.bak
 
 site/
 output/
diff --git a/Makefile b/Makefile
index b75eb2cc..98c17985 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,11 @@ test: ## run unit tests
 	@echo "go test -race -v ./..."
 	@go test -race -v ./...
 
+.PHONY: bump
+bump: ## bump hrp version
+	@echo "[info] bump hrp version"
+	@. cli/scripts/bump_version.sh $(version)
+
 .PHONY: build
 build: ## build hrp cli tool
 	@echo "[info] build hrp cli tool"
diff --git a/boomer.go b/boomer.go
index 49410898..8ec0ff67 100644
--- a/boomer.go
+++ b/boomer.go
@@ -140,7 +140,7 @@ func (b *HRPBoomer) convertBoomerTask(testcase *TestCase) *boomer.Task {
 				if stepData.stepType == stepTypeTransaction {
 					// transaction
 					// FIXME: support nested transactions
-					if stepData.elapsed != 0 { // only record when transaction ends
+					if step.ToStruct().Transaction.Type == transactionEnd { // only record when transaction ends
 						b.RecordTransaction(stepData.name, transactionSuccess, stepData.elapsed, 0)
 						transactionSuccess = true // reset flag for next transaction
 					}
diff --git a/cli/scripts/bump_version.sh b/cli/scripts/bump_version.sh
new file mode 100644
index 00000000..7be0a2b6
--- /dev/null
+++ b/cli/scripts/bump_version.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+# build hrp cli binary for testing
+# release will be triggered on github actions, see .github/workflows/release.yml
+
+# Usage:
+# $ make bump version=v0.5.2
+# or
+# $ bash cli/scripts/bump_version.sh v0.5.2
+
+set -e
+
+version=$1
+
+if [ -z "$version" ]; then
+    echo "version is required"
+    exit 1
+fi
+
+echo "bump hrp version to $version"
+sed -i'.bak' "s/\"v.*\"/\"$version\"/g" internal/version/init.go
+
+echo "bump install.sh version to $version"
+sed -i'.bak' "s/LATEST_VERSION=\"v.*\"/LATEST_VERSION=\"$version\"/g" cli/scripts/install.sh
diff --git a/cli/scripts/install.sh b/cli/scripts/install.sh
index 14573cd8..af495e31 100644
--- a/cli/scripts/install.sh
+++ b/cli/scripts/install.sh
@@ -2,6 +2,8 @@
 # install hrp with one shell command
 # bash -c "$(curl -ksSL https://httprunner.oss-cn-beijing.aliyuncs.com/install.sh)"
 
+LATEST_VERSION="v0.5.2"
+
 set -e
 
 function echoError() {
@@ -46,14 +48,6 @@ function get_pkg_suffix() {
     fi
 }
 
-function get_download_url() {
-    # github
-    # url="https://github.com/httprunner/hrp/releases/download/$version/$1"
-    # aliyun oss
-    url="https://httprunner.oss-cn-beijing.aliyuncs.com/$1"
-    echo $url
-}
-
 function extract_pkg() {
     pkg=$1
     if [[ $pkg == *.zip ]]; then # windows
@@ -67,16 +61,25 @@ function extract_pkg() {
 
 function main() {
     echoInfo "Detect target hrp package..."
-    version=$(get_latest_version)
-    echo "Latest version: $version"
+    version=$LATEST_VERSION
     os=$(get_os)
     echo "Current OS: $os"
     arch=$(get_arch)
     echo "Current ARCH: $arch"
     pkg_suffix=$(get_pkg_suffix $os)
     pkg="hrp-$version-$os-$arch$pkg_suffix"
-    url=$(get_download_url $pkg)
-    echo "Selected package: $url"
+
+    # download from aliyun OSS
+    url="https://httprunner.oss-cn-beijing.aliyuncs.com/$pkg"
+    if ! curl --output /dev/null --silent --head --fail "$url"; then
+        # aliyun OSS url is invalid, try to download from github
+        version=$(get_latest_version)
+        pkg="hrp-$version-$os-$arch$pkg_suffix"
+        url="https://github.com/httprunner/hrp/releases/download/$version/$pkg"
+    fi
+
+    echo "Latest version: $version"
+    echo "Download url: $url"
     echo
 
     echoInfo "Created temp dir..."
@@ -98,10 +101,10 @@ function main() {
     echo
 
     echoInfo "Installing..."
-    if hrp -v > /dev/null; then
+    if hrp -v > /dev/null && [ $(command -v hrp) != "./hrp" ]; then
         echoWarn "$(hrp -v) exists, remove first !!!"
-        echo "$ rm -rf $(which hrp)"
-        rm -rf "$(which hrp)"
+        echo "$ rm -rf $(command -v hrp)"
+        rm -rf "$(command -v hrp)"
     fi
 
     echo "$ chmod +x hrp && mv hrp /usr/local/bin/"
@@ -110,8 +113,8 @@ function main() {
     echo
 
     echoInfo "Check installation..."
-    echo "$ which hrp"
-    which hrp
+    echo "$ command -v hrp"
+    command -v hrp
     echo "$ hrp -v"
     hrp -v
     echo "$ hrp -h"
diff --git a/internal/boomer/output.go b/internal/boomer/output.go
index 70ab8b06..2f05149d 100644
--- a/internal/boomer/output.go
+++ b/internal/boomer/output.go
@@ -337,6 +337,17 @@ var (
 	)
 )
 
+// counter for total
+var (
+	counterErrors = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "errors",
+			Help: "The errors of load testing",
+		},
+		[]string{"method", "name", "error"},
+	)
+)
+
 // summary for total
 var (
 	summaryResponseTime = prometheus.NewSummaryVec(
@@ -399,13 +410,6 @@ var (
 			Help: "The accumulated number of failed transactions",
 		},
 	)
-	gaugeErrors = prometheus.NewGaugeVec(
-		prometheus.GaugeOpts{
-			Name: "errors",
-			Help: "The errors of load testing",
-		},
-		[]string{"method", "name", "error"},
-	)
 )
 
 // NewPrometheusPusherOutput returns a PrometheusPusherOutput.
@@ -436,7 +440,8 @@ func (o *PrometheusPusherOutput) OnStart() {
 		gaugeAverageContentLength,
 		gaugeCurrentRPS,
 		gaugeCurrentFailPerSec,
-		gaugeErrors,
+		// counter for total
+		counterErrors,
 		// summary for total
 		summaryResponseTime,
 		// gauges for total
@@ -505,11 +510,11 @@ func (o *PrometheusPusherOutput) OnEvent(data map[string]interface{}) {
 
 	// errors
 	for _, requestError := range output.Errors {
-		gaugeErrors.WithLabelValues(
+		counterErrors.WithLabelValues(
 			requestError["method"].(string),
 			requestError["name"].(string),
 			requestError["error"].(string),
-		).Set(float64(requestError["occurrences"].(int64)))
+		).Add(float64(requestError["occurrences"].(int64)))
 	}
 
 	if err := o.pusher.Push(); err != nil {