diff --git a/Cargo.toml b/Cargo.toml
index 1d0e182..eff6849 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "logging"
-version = "0.4.1"
+version = "0.4.2"
 authors = ["Jonathan Strong <jstrong@legis.io>"]
 
 [[example]]
@@ -25,6 +25,7 @@ fnv = "1"
 uuid = { version = "0.5", features = ["serde", "v4"] }
 hdrhistogram = "6"
 slog-async = "2"
+smallvec = "0.6"
 
 sloggers = { path = "../sloggers" }
 
diff --git a/src/influx.rs b/src/influx.rs
index 70ddca4..9a240ad 100644
--- a/src/influx.rs
+++ b/src/influx.rs
@@ -22,6 +22,7 @@ use ordermap::OrderMap;
 use fnv::FnvHasher;
 use decimal::d128;
 use uuid::Uuid;
+use smallvec::SmallVec;
 
 use super::{nanos, file_logger, LOG_LEVEL};
 #[cfg(feature = "warnings")]
@@ -63,8 +64,8 @@ pub fn new_map<K, V>(capacity: usize) -> Map<K, V> {
 ///     let meas: OwnedMeasurement = rx.recv().unwrap();
 ///
 ///     assert_eq!(meas.key, "test");
-///     assert_eq!(meas.tags.get("color"), Some(&"red"));
-///     assert_eq!(meas.fields.get("n"), Some(&OwnedValue::Integer(1)));
+///     assert_eq!(meas.get_tag("color"), Some("red"));
+///     assert_eq!(meas.get_field("n"), Some(&OwnedValue::Integer(1)));
 ///
 ///     // alternate syntax ...
 ///
@@ -82,10 +83,10 @@ pub fn new_map<K, V>(capacity: usize) -> Map<K, V> {
 ///     let meas: OwnedMeasurement = rx.recv().unwrap();
 ///
 ///     assert_eq!(meas.key, "test");
-///     assert_eq!(meas.tags.get("one"), Some(&"a"));
-///     assert_eq!(meas.tags.get("two"), Some(&"b"));
-///     assert_eq!(meas.fields.get("three"), Some(&OwnedValue::Integer(2)));
-///     assert_eq!(meas.fields.get("seven"), Some(&OwnedValue::Integer(3)));
+///     assert_eq!(meas.get_tag("one"), Some("a"));
+///     assert_eq!(meas.get_tag("two"), Some("b"));
+///     assert_eq!(meas.get_field("three"), Some(&OwnedValue::Integer(2)));
+///     assert_eq!(meas.get_field("seven"), Some(&OwnedValue::Integer(3)));
 ///     assert_eq!(meas.timestamp, Some(1));
 ///
 ///     // use the @make_meas flag to skip sending a measurement, instead merely
@@ -453,7 +454,7 @@ pub fn serialize_owned(measurement: &OwnedMeasurement, line: &mut String) {
         line.push_str(&escape(value));
     };
 
-    for (key, value) in measurement.tags.iter() {
+    for &(key, value) in measurement.tags.iter() {
         add_tag(line, key, value);
     }
 
@@ -481,13 +482,13 @@ pub fn serialize_owned(measurement: &OwnedMeasurement, line: &mut String) {
     // first time separate from tags with space
     //
     fields.next().map(|kv| {
-        add_field(line, kv.0, kv.1, true);
+        add_field(line, &kv.0, &kv.1, true);
     });
 
     // then seperate the rest w/ comma
     //
     for kv in fields {
-        add_field(line, kv.0, kv.1, false);
+        add_field(line, kv.0, &kv.1, false);
     }
 
     if let Some(t) = measurement.timestamp {
@@ -575,8 +576,10 @@ pub enum OwnedValue {
 pub struct OwnedMeasurement {
     pub key: &'static str,
     pub timestamp: Option<i64>,
-    pub fields: Map<&'static str, OwnedValue>,
-    pub tags: Map<&'static str, &'static str>,
+    //pub fields: Map<&'static str, OwnedValue>,
+    //pub tags: Map<&'static str, &'static str>,
+    pub fields: SmallVec<[(&'static str, OwnedValue); 8]>,
+    pub tags: SmallVec<[(&'static str, &'static str); 8]>,
 }
 
 impl OwnedMeasurement {
@@ -584,22 +587,27 @@ impl OwnedMeasurement {
         OwnedMeasurement {
             key,
             timestamp: None,
-            tags: new_map(n_tags),
-            fields: new_map(n_fields),
+            tags: SmallVec::with_capacity(n_tags),
+            fields: SmallVec::with_capacity(n_fields),
         }
     }
 
     pub fn new(key: &'static str) -> Self {
-        OwnedMeasurement::with_capacity(key, 4, 4)
+        OwnedMeasurement {
+            key,
+            timestamp: None,
+            tags: SmallVec::new(),
+            fields: SmallVec::new(),
+        }
     }
 
     pub fn add_tag(mut self, key: &'static str, value: &'static str) -> Self {
-        self.tags.insert(key, value);
+        self.tags.push((key, value));
         self
     }
 
     pub fn add_field(mut self, key: &'static str, value: OwnedValue) -> Self {
-        self.fields.insert(key, value);
+        self.fields.push((key, value));
         self
     }
 
@@ -609,9 +617,33 @@ impl OwnedMeasurement {
     }
 
     pub fn set_tag(mut self, key: &'static str, value: &'static str) -> Self {
-        *self.tags.entry(key).or_insert(value) = value;
-        self
+        match self.tags.iter().position(|kv| kv.0 == key) {
+            Some(i) => {
+                self.tags.get_mut(i)
+                    .map(|x| {
+                        x.0 = value;
+                    });
+                self
+            }
+
+            None => {
+                self.add_tag(key, value)
+            }
+        }
+    }
+
+    pub fn get_field(&self, key: &'static str) -> Option<&OwnedValue> {
+        self.fields.iter()
+            .find(|kv| kv.0 == key)
+            .map(|kv| &kv.1)
     }
+
+    pub fn get_tag(&self, key: &'static str) -> Option<&'static str> {
+        self.tags.iter()
+            .find(|kv| kv.0 == key)
+            .map(|kv| kv.1)
+    }
+
 }
 
 #[allow(unused_imports, unused_variables)]
@@ -626,8 +658,8 @@ mod tests {
         let color = "red";
         let time = now();
         let m = measure!(@make_meas test, t(color), t(tag_value), tm(time));
-        assert_eq!(m.tags.get("color"), Some(&"red"));
-        assert_eq!(m.tags.get("tag_value"), Some(&"one"));
+        assert_eq!(m.get_tag("color"), Some("red"));
+        assert_eq!(m.get_tag("tag_value"), Some("one"));
         assert_eq!(m.timestamp, Some(time));
     }
 
@@ -635,9 +667,9 @@ mod tests {
     fn it_uses_measure_macro_parenthesis_syntax() {
         let m = measure!(@make_meas test, t(a,"b"), i(n,1), f(x,1.1), tm(1));
         assert_eq!(m.key, "test");
-        assert_eq!(m.tags.get("a"), Some(&"b"));
-        assert_eq!(m.fields.get("n"), Some(&OwnedValue::Integer(1)));
-        assert_eq!(m.fields.get("x"), Some(&OwnedValue::Float(1.1)));
+        assert_eq!(m.get_tag("a"), Some("b"));
+        assert_eq!(m.get_field("n"), Some(&OwnedValue::Integer(1)));
+        assert_eq!(m.get_field("x"), Some(&OwnedValue::Float(1.1)));
         assert_eq!(m.timestamp, Some(1));
     }
 
@@ -696,7 +728,7 @@ mod tests {
         let (tx, rx) = channel();
         measure!(tx, test, tag[color;"red"], int[n;1]);
         let meas: OwnedMeasurement = rx.recv().unwrap();
-        assert_eq!(meas.tags.get("color"), Some(&"red"), "meas = \n {:?} \n", meas);
+        assert_eq!(meas.get_tag("color"), Some("red"), "meas = \n {:?} \n", meas);
     }
 
     #[test]
@@ -712,10 +744,10 @@ mod tests {
             time [ 1 ]
         );
         assert_eq!(meas.key, "test_measurement");
-        assert_eq!(meas.tags.get("one"), Some(&"a"));
-        assert_eq!(meas.tags.get("two"), Some(&"b"));
-        assert_eq!(meas.fields.get("three"), Some(&OwnedValue::Integer(2)));
-        assert_eq!(meas.fields.get("seven"), Some(&OwnedValue::Integer(3)));
+        assert_eq!(meas.get_tag("one"), Some("a"));
+        assert_eq!(meas.get_tag("two"), Some("b"));
+        assert_eq!(meas.get_field("three"), Some(&OwnedValue::Integer(2)));
+        assert_eq!(meas.get_field("seven"), Some(&OwnedValue::Integer(3)));
         assert_eq!(meas.timestamp, Some(1));
     }
 
@@ -735,10 +767,10 @@ mod tests {
         thread::sleep(Duration::from_millis(10));
         let meas: OwnedMeasurement = rx.try_recv().unwrap();
         assert_eq!(meas.key, "test_measurement");
-        assert_eq!(meas.tags.get("one"), Some(&"a"));
-        assert_eq!(meas.tags.get("two"), Some(&"b"));
-        assert_eq!(meas.fields.get("three"), Some(&OwnedValue::Integer(2)));
-        assert_eq!(meas.fields.get("seven"), Some(&OwnedValue::Integer(3)));
+        assert_eq!(meas.get_tag("one"), Some("a"));
+        assert_eq!(meas.get_tag("two"), Some("b"));
+        assert_eq!(meas.get_field("three"), Some(&OwnedValue::Integer(2)));
+        assert_eq!(meas.get_field("seven"), Some(&OwnedValue::Integer(3)));
         assert_eq!(meas.timestamp, Some(1));
     }
 
@@ -759,9 +791,9 @@ mod tests {
         thread::sleep(Duration::from_millis(10));
         let meas: OwnedMeasurement = rx.try_recv().unwrap();
         assert_eq!(meas.key, "test_measurement");
-        assert_eq!(meas.tags.get("one"), Some(&"a"));
-        assert_eq!(meas.fields.get("two"), Some(&OwnedValue::D128(d128::zero())));
-        assert_eq!(meas.fields.get("three"), Some(&OwnedValue::Uuid(u)));
+        assert_eq!(meas.get_tag("one"), Some("a"));
+        assert_eq!(meas.get_field("two"), Some(&OwnedValue::D128(d128::zero())));
+        assert_eq!(meas.get_field("three"), Some(&OwnedValue::Uuid(u)));
         assert_eq!(meas.timestamp, Some(t));
     }
 
@@ -783,10 +815,10 @@ mod tests {
         thread::sleep(Duration::from_millis(10));
         let meas: OwnedMeasurement = rx.try_recv().unwrap();
         assert_eq!(meas.key, "test_measurement");
-        assert_eq!(meas.tags.get("one"), Some(&"a"));
-        assert_eq!(meas.tags.get("two"), Some(&"b"));
-        assert_eq!(meas.fields.get("three"), Some(&OwnedValue::Integer(2)));
-        assert_eq!(meas.fields.get("seven"), Some(&OwnedValue::Integer(3)));
+        assert_eq!(meas.get_tag("one"), Some("a"));
+        assert_eq!(meas.get_tag("two"), Some("b"));
+        assert_eq!(meas.get_field("three"), Some(&OwnedValue::Integer(2)));
+        assert_eq!(meas.get_field("seven"), Some(&OwnedValue::Integer(3)));
         assert_eq!(meas.timestamp, Some(1));
     }
 
@@ -794,8 +826,8 @@ mod tests {
     fn it_checks_that_fields_are_separated_correctly() {
         let m = measure!(@make_meas test, t[a; "one"], t[b; "two"], f[x; 1.1], f[y; -1.1]);
         assert_eq!(m.key, "test");
-        assert_eq!(m.tags.get("a"), Some(&"one"));
-        assert_eq!(m.fields.get("x"), Some(&OwnedValue::Float(1.1)));
+        assert_eq!(m.get_tag("a"), Some("one"));
+        assert_eq!(m.get_field("x"), Some(&OwnedValue::Float(1.1)));
 
         let mut buf = String::new();
         serialize_owned(&m, &mut buf);
@@ -821,7 +853,7 @@ mod tests {
 
         let m = measure!(@make_meas test, t(name, "a"), i(a, b.a.one));
 
-        assert_eq!(m.fields.get("a"), Some(&OwnedValue::Integer(1)));
+        assert_eq!(m.get_field("a"), Some(&OwnedValue::Integer(1)));
     }
 
     #[bench]
diff --git a/src/lib.rs b/src/lib.rs
index b487026..b432dc7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,6 +22,7 @@ extern crate ordermap;
 extern crate decimal;
 extern crate uuid;
 extern crate hdrhistogram;
+extern crate smallvec;
 
 extern crate windows;
 extern crate pubsub as pub_sub;